[Objective] This study aimed to investigate the mutagenic effect of cobalt- 60 irradiation on potato. [Method] Potato tubers of Favorita and Zhongshu No.3 were irradiated with 5, 10, 20, 30, 50 and 70 Gy of cobalt-60 ...[Objective] This study aimed to investigate the mutagenic effect of cobalt- 60 irradiation on potato. [Method] Potato tubers of Favorita and Zhongshu No.3 were irradiated with 5, 10, 20, 30, 50 and 70 Gy of cobalt-60 γ-ray respectively, to explore the mutagenic effect of different doses of γ-ray heavy ion irradiation on potato. [Result] The results showed that the emergence rate, seedling rate, plant growth, yield and commodity of potato varied after irradiated with different doses of cobalt-60 γ-ray; 10Gy of cobalt-60 irradiation played a positive effect on the growth and development of potato, while high doses played a negative effect on the growth and development of potato. After cobalt-60 irradiation, the botanical traits of M1 gen- eration varied greatly, resulting in a number of beneficial mutation traits; some traits of M2 and M3 generations became stably inherited. [Conclusion] Cobalt-60 irradiation breeding is conducive to the variety improvement and germplasm innovation as an effective means of genetic improvement for potato.展开更多
Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, a...Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, are common in many ecosystems. The strategies by which clonal plants adapt to this type of heterogeneous environment were examined in three stoloniferous herbs,Potentilla reptans L. var. sericophylla Franch., P. anserina L. and Halerpestes ruthenica (Jacq.) Qvcz., commonly inhabiting forest understories, grasslands and low saline meadows, respectively. As pairs of connected ramets were subjected to reciprocal patchiness of light and nutrients, stolon connection between the two ramets significantly enhanced biomass of both ramet growing in low light intensity but high soil nutrient condition (LH ramet) and ramet growing in high light intensity but low soil nutrient condition (HL ramet) as well as whole ramet pairs (consisting of LH ramets and HL ramets). Additionally, stolon connection greatly increased root/shoot ratio of LH ramet while significantly decreased that of HL ramet. The results indicate that a reciprocal transportation of resources between interconnected ramets and a functional specialization of ramets in uptake of abundant resources occurred. By resource sharing and functional specialization, clonal plants can efficiently acquire locally abundant resources and buffer the stress caused by reciprocal patchiness of resources.展开更多
The structure of tubeimoside V (1), a new cyclic bisdesmoside, isolated from tubers of Bolbostemma paniculatum (Tu Bei Mu), was established by means of 2D NMR spectral and chemical methods. Compound 1 has inter-saccha...The structure of tubeimoside V (1), a new cyclic bisdesmoside, isolated from tubers of Bolbostemma paniculatum (Tu Bei Mu), was established by means of 2D NMR spectral and chemical methods. Compound 1 has inter-saccharide chain bridging by a dicrotalic acid to form a unique macrocyclic structure.展开更多
AIM: To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index (GI) of Chinese food.METHODS: Food containing 50 g carbohydrate was consumed by 8-12 h...AIM: To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index (GI) of Chinese food.METHODS: Food containing 50 g carbohydrate was consumed by 8-12 healthy adults after they have been fasted for 10 h and blood glucose was monitored for 2 h. Glucose was used as reference food. GI of food was calculated according to a standard method.RESULTS: GI of 9 types of sugar and 60 kinds of food were determined.CONCLUSION: Food GI is mainly determined by nature of carbohydrate and procession. Most of cereals and tubers produced in China have similar GI with their counterparts produced in other countries.展开更多
Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging diseases of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya, potato tuber yield losses due to BW infection are estimated...Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging diseases of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya, potato tuber yield losses due to BW infection are estimated at 50 ~ 100%. Low soil fertility is also one of the most important constraints limiting potato production in central Kenya highlands. Farmers tackle this problem through use of inorganic fertilisers and organic manures, both of which amend the soil environment to influence bacterial wilt development. Undecomposed organic manures can also introduce the pathogen into a clean field. Between short rains 1999 and 2000, 10 on-farm extension-researcher- farmer-designed and farmer-managed trials were done at Kianjuki catchment in Embu District. The objective was to use farmers?participatory research approach and select the most suitable organic and inorganic fertiliser combination(s) with lowest BWI and acceptable usable tuber yields, and also to demonstrate use of some components of integrated disease management methods in reduction of disease incidence and spread. Seven treatments were proposed, presented to the farmers for discussion and the most relevant four were selected for evaluation. A newly released potato variety 慉sante?was planted during the short rains 1999 and long rains 2000. BWI didn抰 result in significant differences between treatments but the tuber yields were significantly different in short rains of 1999 and 2000. During short rains 2000, both BWI and tuber yields and unusable tubers differed significantly between treatments. The results confirmed that well- decomposed manures or manures from pathogen-free areas can be used in combination with inorganic fertilisers to improve soil fertility and potato tuber yields in smallholder farms without influencing BWI. Use of certified seed tubers in pathogen free field and following recommended field sanitation measures resulted in apparently bacterial wilt free crop. Considering the high cost of inorganic fertiliser and its negative effects on the environment, reduced usage at half the recommended rates combined with half rates of FYM is feasible option friendly to the farmer, soil and environment. The interviewed farmers also ranked the option as the most appropriate combination for soil fertility improvement for potato production in smallholder farms.展开更多
Yam, Dioscorea esculenta which is a high value commodity is a threatened species in Ghana, due to several factors including neglect on the part of science, technology, research and development. Different doses of radi...Yam, Dioscorea esculenta which is a high value commodity is a threatened species in Ghana, due to several factors including neglect on the part of science, technology, research and development. Different doses of radiation were use to improve the size and market value of D. esculenta to promote it effective use and enhance effective conservation. We observed through repeated experiments that irradiation of yam planting material at 40 Gy gave the best results producing a M1 generation with a decreased number of tubers but with an increased tuber size per vine. Some yam characteristics are valued more than others, and prices vary across species, time, and market sites. Tuber weight exhibits an increasing marginal value and price per kilogram increases above an optimum size; therefore, yam producers and dealers derive additional reward from extra-large tubers. We conclude that, to effectively access and benefit from urban markets, producers should focus on the improved size and conical shaped-tubers, which are easy to process and meet the aesthetic qualities preferred by urban consumers. The implications for research on improved variety development to reduce poverty and for crop and resource management practices are drawn.展开更多
Abstract: Raphunus sativus L. commonly known as "radish" is a popular vegetable crop used by people all over the world for its culinary and medicinal properties. Enhancement of in vitro regeneration system for radi...Abstract: Raphunus sativus L. commonly known as "radish" is a popular vegetable crop used by people all over the world for its culinary and medicinal properties. Enhancement of in vitro regeneration system for radish variety beeralu is needed to further tissue culture studied. Therefore, the present study was carried out to find out the effects of different organic additives on in vitro shoot regeneration of Radish (Raphanus sativus L.) Var. Beeralu. Hypocotyl explants of aseptic plantlets were cultured on MS basal medium supplemented with 2.5 mg/L BAP (benzyl adenine) and 0.1 mg/L NAA (1-nphthaleneacetic acid) with different natural additives; 20% coconut water, 20% coconut milk, 10% grind spinach leaves, 10% grind potato tubers, 10% grind carrot, 5% rice flour, 10% green gram, 10% grind pumpkin, 10% banana fruit, 10% orange and control (without any additives). Complete randomized design (CRD) with five replicates was used. After one month the numbers of regenerated shoots were counted and statistical analysis was carried out using the Student Newman-Kuells Means Separation Test of SAS program (9.1.3). The highest mean number of shoots (12 shoots/explant) from Radish (Raphanus sativus L.) Var. Beeralu observed in MS basal medium with 2.5 mg/L BAP and 0.1 mg/L NAA with 10% orange juice whereas the 2nd highest shoots were obtained with 20% coconut water. The lowest number of shoots (0 shoot/explant) was observed from medium with carrot juice and pumpkin juice, but they induced callus formation. Media with grind spinach leaves, rice flour, green gram, grind potato tubers and banana inhibit the shoot regeneration.展开更多
Konjac (Amorphophallus muelleri), a genus of tuberous plants in the Araceae family, is one of high-value crops in Southwest China. This study aimed at identifying the main pathogens causing tuber rot during storage ...Konjac (Amorphophallus muelleri), a genus of tuberous plants in the Araceae family, is one of high-value crops in Southwest China. This study aimed at identifying the main pathogens causing tuber rot during storage ofA. muelleri and screening the effective fungicides, so as to prolong the storage period ofA. muelleri and decrease the losses. Isolation and identification, as well as pathogenicity test and retro-inoculation experiments were made for the pathogen causing tuber rot during storage ofA. muelleri in Kunming city, Yunnan province, China. The effective fungicides for the main pathogens were also screened in the laboratory. Six fungi were identified as the pathogens causing tuber rot of A. muelleri, which were Fusarium solani (Mart,) Sacc., Fusarium oxysporum Schlecht., Botrytis cinerea Pers., Alternaria alternata (Fr.) Keissl., Rhizopus nigricans Ehrenb., Penicillium ulaiense Hsieh, Su & Tzean. The main pathogens causing postharvest diseases ofA. muelleri were F. solani, F. oxysporum and B. cinerea. The isolation frequencies of them were 33.9%, 10.5% and 19.4%, respectively. After artificial inoculation, the incidence of tubers infected by F. solani, F. oxysporum and B. cinerea was 100%, 83% and 95%, respectively. The results of chemical screening showed that, in potato dextrose agar (PDA) media plate, the compounds Fludioxonil (50% WP) and Boscalid (50% WG) were the most effective in controlling the three main pathogens, and the average effect reached more than 97%. The test of fungicidal antisepsis on tubers consisted ofA. muelleri being dipped in the 9,000x diluted solution of Fludioxonil (50% WP) or in the 3,500x diluted solution of Boscalid (50% WG) for 3 min and stored at room temperature (25 ℃) for 7 d and 15 d, respectively. The fungicidal effects of Fludioxonil against F. solani, F. oxysporum and B. cinerea for 7 d and 15 d were 88.6%/83.2%, 90.1%/84.7% and 93.0%/91.5%, respectively, whereas the fungicidal effects of Boscalid were 87.0%/85.3%, 89.0%/85.6% and 89.2%/89.1%, respectively. The results may provide useful information for the control ofpostharvest diseases ofA. muelleri.展开更多
The aim of this study was to test the ef fects of including sweet potato tuber and stem powder in feed on the body composition and digestive enzyme activities of the sea cucumber A postichopus japonicas Selenka. Dif f...The aim of this study was to test the ef fects of including sweet potato tuber and stem powder in feed on the body composition and digestive enzyme activities of the sea cucumber A postichopus japonicas Selenka. Dif ferent proportions of sweet potato tuber and stem powders(from 10% to 50%) were added into compound feeds, which were supplied to A. japonicas during a 60-day experiment. The results showed that the two sweet potato ingredients had different eff ects on the nutrient contents of the sea cucumber body wall. The group supplied with feed containing 20% sweet potato tuber powder(T2) had the highest level of crude protein in body walls(P <0.05), while there were no significant dif ferences in the moisture and ash contents of body walls among the groups(P >0.05). In all the groups fed with powdered sweet potato tubers(T groups), the proportions of glutamic acid and lysine in body walls were higher than those in the control, whereas the proportion of methionine decreased slightly. Diff erent proportions of sweet potato ingredients in compound feeds also af fected digestive enzyme activities in the sea cucumbers. The activities of protease and lipase first increased and then gradually decreased with increasing proportions of sweet potato materials in the feed. The highest protease activity was in the T2 and the group and the highest lipase activity was in the 10% sweet potato stem(S1) group. These results show that feed components can stimulate digestive enzyme activities in sea cucumber, and that the proportions of tubers and stems of sweet potato in feed can be adjusted to improve the digestion and growth of A. japonicas in marine farms.展开更多
[Objective] The influences of different habitats on asexual propagation of wild Geg(abbreviation for Gastrodia elata Bl. f. glauca S. Chow) being domesticated in Ganzi prefecture was studied. [Method] The research tri...[Objective] The influences of different habitats on asexual propagation of wild Geg(abbreviation for Gastrodia elata Bl. f. glauca S. Chow) being domesticated in Ganzi prefecture was studied. [Method] The research trial was carried out in the following three kinds of habitats at the same time: the plastic greenhouses, the birch forest of shady slope and the shrubbery of sunny slope, and the results were analyzed with group data average hypothesis test method. [Result] The overall tuber(the juvenile tuber, the immature tuber and the mature tuber) yield and the mature tuber yield were both very significantly higher in the plastic greenhouses than in the other two types of habitats, and respectively reached 9.52 and 6.70 kg/m2; the mature tuber drying rate was dramatically or very dramatically lower in the plastic greenhouses than in the other two types of habitats, and was 23.84%; the stabilities of the overall tuber yield, the mature tuber yield and the drying rate were all reduced in the order of greenhouses, birch forest and shrubbery; and the dry mature tuber yield of the plastic greenhouses was the highest in the three kinds of habitats, and was 1.60 kg/m2. [Conclusion] A good habitat had to be created or chosen in the domesticating cultivation of the wild Geg in Ganzi prefecture. The preferred choice was the plastic greenhouse, the alternative one was the deciduous broadleaved forest of shady slope. The imitating wild planting of the wild Geg should be done in the warm moist deciduous broad-leaved forest of shady slope.展开更多
In a completely randomized blocks (RCB) plot, we planted seed from the three segments of Kponan tubers: head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sproutin...In a completely randomized blocks (RCB) plot, we planted seed from the three segments of Kponan tubers: head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sprouting rate of the Kponan full season harvest tuber was 78.1% compared to 94% in Krengle. However, the tuber germination was progressive from head to tail with a linear evolution of the top fragments with sprouting rate up to 90% similar to Krengle. The median and distal portions sprout two and three weeks later with final raising rates reaching 68% and 71%, respectively. The full season tuber of Kponan sprouts with a good rate gave good yields for any portion of the tuber. It had a sprouting gradient oriented from the proximal portion to the distal one, while yield was better for medium seeds. The sprouting delays two weeks between proximal and medium portions and three weeks between proximal and distal portions were acceptable with regards to the total cycle of eight to nine months period. Thus, its small tubers could be planted as well as the top portion of big tuber. In terms of yield, Kponan medium seed gave the best yield 34.25 t/ha and the whole Kponan tuber yield was more than Krengle. That led to a better multiplication factor for Kponan full season tuber. The type of tuber, if available, could be used as seed for yam production. That could improve its distribution and contribute to food security.展开更多
Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them w...Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits: time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight (tuber yield), tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. (water yam) on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.展开更多
In Western culture, the symbol of the tree which divides into branches and has a foliage of the same lineage as its roots is the best symbol for describing identity and also for describing the Cartesian reasoning whic...In Western culture, the symbol of the tree which divides into branches and has a foliage of the same lineage as its roots is the best symbol for describing identity and also for describing the Cartesian reasoning which proceeds by eliminating misconceptions and following thesingle true idea. In the West Indies culture, it is the rhizome that is the best symbol to describe the identity of these peoples. The rhizome as explained by Deleuze and Gattari in their Introduction Rhizome of the book .4 thousand plateaus, is a tuber that makes roots after being cut off from its original plant. In this respect, it is most appropriate to describe the people of the Caribbean who have been cut off from their African roots by slavery but who have thrived on the island, re-establishing links with the different peoples who came to work there. The rhizome is similar to the mangrove that protects the island from marine erosion, it intertwines with other plants so that it is impossible to distinguish the source plant. In this respect, it is the best symbol to describe the creole identity and the refusal of the West Indians to return to a racial and social system that promulgated the white race as superior to the black race during colonialism. The structure of the books of Maryse Cond6 is itself rhizomatic since it does not present the theme of its stories through the view point of an omnipotent author but through the view points of all the characters of the novel who by their discussions letthe reader discover their terrible history of slavery, and transform himinto a new man who would seek diversity.展开更多
In the years 2008-2010, an experiment was conducted Phytophthora infestans under organic and conventional production on four potato cultivars differing in maturity and resistance to systems. During the growing season,...In the years 2008-2010, an experiment was conducted Phytophthora infestans under organic and conventional production on four potato cultivars differing in maturity and resistance to systems. During the growing season, plant growth was evaluated by measuring plant height, stem number, leaf and stem biomass and leaf area index (LAI). Photosynthetic active radiation (PAR) absorption and leaf chlorophyll content were also measured. The rate of late blight development, tuber yield, tuber size, and harvest index was assessed. There were significant differences between the two production systems in the most studied parameters. Plants growing in the organic system were characterized by reduced plant development compared to plants growing in the conventional system. As a result of lower plant growth, tuber yield was reduced by 22% and tuber size was smaller. Harvest index did not differ significantly between production systems. A positive effect of the reduced development of aboveground plant parts in the organic system was later appearance of the first symptoms of late blight and slower spread the disease.展开更多
In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. T...In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. The influence of such factors as the crop production system (organic and integrated), the place of production (soil quality), variety and years of research on the chemical composition, i.e., tuber dry matter, starch, vitamin C, nitrates and glycoalkaloids were tested. It has been found that the greatest impact on the chemical composition of tubers had the climatic conditions during the growing season and genotype. They affected the contents of all tested components. The place of production affected the contents of dry matter, starch, vitamin C and nitrates. This factor had no effect on the content of glycoalkaloids. The least effect on the chemical tubers composition was in crop production system. It only affected the contents of dry matter, starch and vitamin C. There was no significant effect of this factor on the nitrate and glycoalkaloids content.展开更多
The viability of most tomato varieties cultivated in Libya have been tested to infect with potato spindle tuber viroid/potatoes (PSTVd) and its impact on growth and production of some of these varieties, which were ...The viability of most tomato varieties cultivated in Libya have been tested to infect with potato spindle tuber viroid/potatoes (PSTVd) and its impact on growth and production of some of these varieties, which were mechanically inoculated with Libyan isolate of viroid PSTVd as follows: Vlkato, Sankarh, Lebda, Jasmine, Kenza and Hana. The percent of incidence were 95.95%, 90%, 90.80%, 80% and 20%, respectively. The following varieties have been contagious mechanically with viroid of PSTVd: Vlkato, zahra, Toria, Lebda, Hoda, Farwa, Alkaraz, Naziha, Rim Star and Kartika. The percent of incidence were 95.95%, 85%, 85.80%, 80%, 70.40%, 0.0%, 0.0%, respectively. The varied symptoms of wrinkle, twist, warp, swell the veins of the leaves, dark brown spots formation and a large yellow spots turned into white patches. Also the effect of the Egyptian isolate viroid PSTVd in the growth and production of varieties Jasmine, Lebda, Soberhalim, and treasure No. 185 had been studied, as the average rates of decline in the production of the fruits tomatoes/tomato 43.4% and 17% length of plants, and in the fresh weight and dry root of the sum of 35% and 37% respictively.展开更多
基金Supported by Youth Fund of President of Anhui Academy of Agricultural Sciences (11B0324)~~
文摘[Objective] This study aimed to investigate the mutagenic effect of cobalt- 60 irradiation on potato. [Method] Potato tubers of Favorita and Zhongshu No.3 were irradiated with 5, 10, 20, 30, 50 and 70 Gy of cobalt-60 γ-ray respectively, to explore the mutagenic effect of different doses of γ-ray heavy ion irradiation on potato. [Result] The results showed that the emergence rate, seedling rate, plant growth, yield and commodity of potato varied after irradiated with different doses of cobalt-60 γ-ray; 10Gy of cobalt-60 irradiation played a positive effect on the growth and development of potato, while high doses played a negative effect on the growth and development of potato. After cobalt-60 irradiation, the botanical traits of M1 gen- eration varied greatly, resulting in a number of beneficial mutation traits; some traits of M2 and M3 generations became stably inherited. [Conclusion] Cobalt-60 irradiation breeding is conducive to the variety improvement and germplasm innovation as an effective means of genetic improvement for potato.
文摘Environments with reciprocal patchiness of resources, in which the availability of two resources such as light and soil nutrients are patchily distributed in horizontal space and negatively correlated in each patch, are common in many ecosystems. The strategies by which clonal plants adapt to this type of heterogeneous environment were examined in three stoloniferous herbs,Potentilla reptans L. var. sericophylla Franch., P. anserina L. and Halerpestes ruthenica (Jacq.) Qvcz., commonly inhabiting forest understories, grasslands and low saline meadows, respectively. As pairs of connected ramets were subjected to reciprocal patchiness of light and nutrients, stolon connection between the two ramets significantly enhanced biomass of both ramet growing in low light intensity but high soil nutrient condition (LH ramet) and ramet growing in high light intensity but low soil nutrient condition (HL ramet) as well as whole ramet pairs (consisting of LH ramets and HL ramets). Additionally, stolon connection greatly increased root/shoot ratio of LH ramet while significantly decreased that of HL ramet. The results indicate that a reciprocal transportation of resources between interconnected ramets and a functional specialization of ramets in uptake of abundant resources occurred. By resource sharing and functional specialization, clonal plants can efficiently acquire locally abundant resources and buffer the stress caused by reciprocal patchiness of resources.
文摘The structure of tubeimoside V (1), a new cyclic bisdesmoside, isolated from tubers of Bolbostemma paniculatum (Tu Bei Mu), was established by means of 2D NMR spectral and chemical methods. Compound 1 has inter-saccharide chain bridging by a dicrotalic acid to form a unique macrocyclic structure.
基金Supported by grants from the Ministry of Health in China, No 98-1-063
文摘AIM: To determine the GI of some cereals and tubers produced in China in an effort to establish the database of glycemic index (GI) of Chinese food.METHODS: Food containing 50 g carbohydrate was consumed by 8-12 healthy adults after they have been fasted for 10 h and blood glucose was monitored for 2 h. Glucose was used as reference food. GI of food was calculated according to a standard method.RESULTS: GI of 9 types of sugar and 60 kinds of food were determined.CONCLUSION: Food GI is mainly determined by nature of carbohydrate and procession. Most of cereals and tubers produced in China have similar GI with their counterparts produced in other countries.
文摘Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging diseases of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya, potato tuber yield losses due to BW infection are estimated at 50 ~ 100%. Low soil fertility is also one of the most important constraints limiting potato production in central Kenya highlands. Farmers tackle this problem through use of inorganic fertilisers and organic manures, both of which amend the soil environment to influence bacterial wilt development. Undecomposed organic manures can also introduce the pathogen into a clean field. Between short rains 1999 and 2000, 10 on-farm extension-researcher- farmer-designed and farmer-managed trials were done at Kianjuki catchment in Embu District. The objective was to use farmers?participatory research approach and select the most suitable organic and inorganic fertiliser combination(s) with lowest BWI and acceptable usable tuber yields, and also to demonstrate use of some components of integrated disease management methods in reduction of disease incidence and spread. Seven treatments were proposed, presented to the farmers for discussion and the most relevant four were selected for evaluation. A newly released potato variety 慉sante?was planted during the short rains 1999 and long rains 2000. BWI didn抰 result in significant differences between treatments but the tuber yields were significantly different in short rains of 1999 and 2000. During short rains 2000, both BWI and tuber yields and unusable tubers differed significantly between treatments. The results confirmed that well- decomposed manures or manures from pathogen-free areas can be used in combination with inorganic fertilisers to improve soil fertility and potato tuber yields in smallholder farms without influencing BWI. Use of certified seed tubers in pathogen free field and following recommended field sanitation measures resulted in apparently bacterial wilt free crop. Considering the high cost of inorganic fertiliser and its negative effects on the environment, reduced usage at half the recommended rates combined with half rates of FYM is feasible option friendly to the farmer, soil and environment. The interviewed farmers also ranked the option as the most appropriate combination for soil fertility improvement for potato production in smallholder farms.
文摘Yam, Dioscorea esculenta which is a high value commodity is a threatened species in Ghana, due to several factors including neglect on the part of science, technology, research and development. Different doses of radiation were use to improve the size and market value of D. esculenta to promote it effective use and enhance effective conservation. We observed through repeated experiments that irradiation of yam planting material at 40 Gy gave the best results producing a M1 generation with a decreased number of tubers but with an increased tuber size per vine. Some yam characteristics are valued more than others, and prices vary across species, time, and market sites. Tuber weight exhibits an increasing marginal value and price per kilogram increases above an optimum size; therefore, yam producers and dealers derive additional reward from extra-large tubers. We conclude that, to effectively access and benefit from urban markets, producers should focus on the improved size and conical shaped-tubers, which are easy to process and meet the aesthetic qualities preferred by urban consumers. The implications for research on improved variety development to reduce poverty and for crop and resource management practices are drawn.
文摘Abstract: Raphunus sativus L. commonly known as "radish" is a popular vegetable crop used by people all over the world for its culinary and medicinal properties. Enhancement of in vitro regeneration system for radish variety beeralu is needed to further tissue culture studied. Therefore, the present study was carried out to find out the effects of different organic additives on in vitro shoot regeneration of Radish (Raphanus sativus L.) Var. Beeralu. Hypocotyl explants of aseptic plantlets were cultured on MS basal medium supplemented with 2.5 mg/L BAP (benzyl adenine) and 0.1 mg/L NAA (1-nphthaleneacetic acid) with different natural additives; 20% coconut water, 20% coconut milk, 10% grind spinach leaves, 10% grind potato tubers, 10% grind carrot, 5% rice flour, 10% green gram, 10% grind pumpkin, 10% banana fruit, 10% orange and control (without any additives). Complete randomized design (CRD) with five replicates was used. After one month the numbers of regenerated shoots were counted and statistical analysis was carried out using the Student Newman-Kuells Means Separation Test of SAS program (9.1.3). The highest mean number of shoots (12 shoots/explant) from Radish (Raphanus sativus L.) Var. Beeralu observed in MS basal medium with 2.5 mg/L BAP and 0.1 mg/L NAA with 10% orange juice whereas the 2nd highest shoots were obtained with 20% coconut water. The lowest number of shoots (0 shoot/explant) was observed from medium with carrot juice and pumpkin juice, but they induced callus formation. Media with grind spinach leaves, rice flour, green gram, grind potato tubers and banana inhibit the shoot regeneration.
基金This research was supported by the Science Foundation No. 2011FZ 178, 2011FZ 180, 2014HD004, 14C26215303260 and National Natural Science Foundation of China (NSFC) No. 31260073, 31340019, 31160412, 41361056.
文摘Konjac (Amorphophallus muelleri), a genus of tuberous plants in the Araceae family, is one of high-value crops in Southwest China. This study aimed at identifying the main pathogens causing tuber rot during storage ofA. muelleri and screening the effective fungicides, so as to prolong the storage period ofA. muelleri and decrease the losses. Isolation and identification, as well as pathogenicity test and retro-inoculation experiments were made for the pathogen causing tuber rot during storage ofA. muelleri in Kunming city, Yunnan province, China. The effective fungicides for the main pathogens were also screened in the laboratory. Six fungi were identified as the pathogens causing tuber rot of A. muelleri, which were Fusarium solani (Mart,) Sacc., Fusarium oxysporum Schlecht., Botrytis cinerea Pers., Alternaria alternata (Fr.) Keissl., Rhizopus nigricans Ehrenb., Penicillium ulaiense Hsieh, Su & Tzean. The main pathogens causing postharvest diseases ofA. muelleri were F. solani, F. oxysporum and B. cinerea. The isolation frequencies of them were 33.9%, 10.5% and 19.4%, respectively. After artificial inoculation, the incidence of tubers infected by F. solani, F. oxysporum and B. cinerea was 100%, 83% and 95%, respectively. The results of chemical screening showed that, in potato dextrose agar (PDA) media plate, the compounds Fludioxonil (50% WP) and Boscalid (50% WG) were the most effective in controlling the three main pathogens, and the average effect reached more than 97%. The test of fungicidal antisepsis on tubers consisted ofA. muelleri being dipped in the 9,000x diluted solution of Fludioxonil (50% WP) or in the 3,500x diluted solution of Boscalid (50% WG) for 3 min and stored at room temperature (25 ℃) for 7 d and 15 d, respectively. The fungicidal effects of Fludioxonil against F. solani, F. oxysporum and B. cinerea for 7 d and 15 d were 88.6%/83.2%, 90.1%/84.7% and 93.0%/91.5%, respectively, whereas the fungicidal effects of Boscalid were 87.0%/85.3%, 89.0%/85.6% and 89.2%/89.1%, respectively. The results may provide useful information for the control ofpostharvest diseases ofA. muelleri.
基金Supported by the Natural Science Foundation of Shandong Province(No.ZR2014CQ056)the Innovation Team Building of Sea Cucumber Industry in Shandong Province Modern Agricultural Technology System(Nos.SDAIT-22-01,SDAIT-22-05)+3 种基金the Taishan Industry Leading Talents Project(No.2016-2020)the Agricultural Seed Engineering Project of Shandong Province(No.2017LZGC010)the Science and Technology Development Planning Project in Shandong Province(No.2014GNC111022)the Spark Science and Technology Demonstration Project in Shandong Province(No.2015XH006)
文摘The aim of this study was to test the ef fects of including sweet potato tuber and stem powder in feed on the body composition and digestive enzyme activities of the sea cucumber A postichopus japonicas Selenka. Dif ferent proportions of sweet potato tuber and stem powders(from 10% to 50%) were added into compound feeds, which were supplied to A. japonicas during a 60-day experiment. The results showed that the two sweet potato ingredients had different eff ects on the nutrient contents of the sea cucumber body wall. The group supplied with feed containing 20% sweet potato tuber powder(T2) had the highest level of crude protein in body walls(P <0.05), while there were no significant dif ferences in the moisture and ash contents of body walls among the groups(P >0.05). In all the groups fed with powdered sweet potato tubers(T groups), the proportions of glutamic acid and lysine in body walls were higher than those in the control, whereas the proportion of methionine decreased slightly. Diff erent proportions of sweet potato ingredients in compound feeds also af fected digestive enzyme activities in the sea cucumbers. The activities of protease and lipase first increased and then gradually decreased with increasing proportions of sweet potato materials in the feed. The highest protease activity was in the T2 and the group and the highest lipase activity was in the 10% sweet potato stem(S1) group. These results show that feed components can stimulate digestive enzyme activities in sea cucumber, and that the proportions of tubers and stems of sweet potato in feed can be adjusted to improve the digestion and growth of A. japonicas in marine farms.
基金Supported by Key Natural Science Program of the Education Department of Sichuan province(12ZA103)
文摘[Objective] The influences of different habitats on asexual propagation of wild Geg(abbreviation for Gastrodia elata Bl. f. glauca S. Chow) being domesticated in Ganzi prefecture was studied. [Method] The research trial was carried out in the following three kinds of habitats at the same time: the plastic greenhouses, the birch forest of shady slope and the shrubbery of sunny slope, and the results were analyzed with group data average hypothesis test method. [Result] The overall tuber(the juvenile tuber, the immature tuber and the mature tuber) yield and the mature tuber yield were both very significantly higher in the plastic greenhouses than in the other two types of habitats, and respectively reached 9.52 and 6.70 kg/m2; the mature tuber drying rate was dramatically or very dramatically lower in the plastic greenhouses than in the other two types of habitats, and was 23.84%; the stabilities of the overall tuber yield, the mature tuber yield and the drying rate were all reduced in the order of greenhouses, birch forest and shrubbery; and the dry mature tuber yield of the plastic greenhouses was the highest in the three kinds of habitats, and was 1.60 kg/m2. [Conclusion] A good habitat had to be created or chosen in the domesticating cultivation of the wild Geg in Ganzi prefecture. The preferred choice was the plastic greenhouse, the alternative one was the deciduous broadleaved forest of shady slope. The imitating wild planting of the wild Geg should be done in the warm moist deciduous broad-leaved forest of shady slope.
文摘In a completely randomized blocks (RCB) plot, we planted seed from the three segments of Kponan tubers: head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sprouting rate of the Kponan full season harvest tuber was 78.1% compared to 94% in Krengle. However, the tuber germination was progressive from head to tail with a linear evolution of the top fragments with sprouting rate up to 90% similar to Krengle. The median and distal portions sprout two and three weeks later with final raising rates reaching 68% and 71%, respectively. The full season tuber of Kponan sprouts with a good rate gave good yields for any portion of the tuber. It had a sprouting gradient oriented from the proximal portion to the distal one, while yield was better for medium seeds. The sprouting delays two weeks between proximal and medium portions and three weeks between proximal and distal portions were acceptable with regards to the total cycle of eight to nine months period. Thus, its small tubers could be planted as well as the top portion of big tuber. In terms of yield, Kponan medium seed gave the best yield 34.25 t/ha and the whole Kponan tuber yield was more than Krengle. That led to a better multiplication factor for Kponan full season tuber. The type of tuber, if available, could be used as seed for yam production. That could improve its distribution and contribute to food security.
文摘Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam (Dioscorea spp.) production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits: time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight (tuber yield), tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. (water yam) on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.
文摘In Western culture, the symbol of the tree which divides into branches and has a foliage of the same lineage as its roots is the best symbol for describing identity and also for describing the Cartesian reasoning which proceeds by eliminating misconceptions and following thesingle true idea. In the West Indies culture, it is the rhizome that is the best symbol to describe the identity of these peoples. The rhizome as explained by Deleuze and Gattari in their Introduction Rhizome of the book .4 thousand plateaus, is a tuber that makes roots after being cut off from its original plant. In this respect, it is most appropriate to describe the people of the Caribbean who have been cut off from their African roots by slavery but who have thrived on the island, re-establishing links with the different peoples who came to work there. The rhizome is similar to the mangrove that protects the island from marine erosion, it intertwines with other plants so that it is impossible to distinguish the source plant. In this respect, it is the best symbol to describe the creole identity and the refusal of the West Indians to return to a racial and social system that promulgated the white race as superior to the black race during colonialism. The structure of the books of Maryse Cond6 is itself rhizomatic since it does not present the theme of its stories through the view point of an omnipotent author but through the view points of all the characters of the novel who by their discussions letthe reader discover their terrible history of slavery, and transform himinto a new man who would seek diversity.
文摘In the years 2008-2010, an experiment was conducted Phytophthora infestans under organic and conventional production on four potato cultivars differing in maturity and resistance to systems. During the growing season, plant growth was evaluated by measuring plant height, stem number, leaf and stem biomass and leaf area index (LAI). Photosynthetic active radiation (PAR) absorption and leaf chlorophyll content were also measured. The rate of late blight development, tuber yield, tuber size, and harvest index was assessed. There were significant differences between the two production systems in the most studied parameters. Plants growing in the organic system were characterized by reduced plant development compared to plants growing in the conventional system. As a result of lower plant growth, tuber yield was reduced by 22% and tuber size was smaller. Harvest index did not differ significantly between production systems. A positive effect of the reduced development of aboveground plant parts in the organic system was later appearance of the first symptoms of late blight and slower spread the disease.
文摘In the years 2008-2010, a study on the quality of tubers grown in the two crop production systems, i.e., organic and integrated in two locations: Jadwisin--Central and Osiny--South-Eastern of Poland were conducted. The influence of such factors as the crop production system (organic and integrated), the place of production (soil quality), variety and years of research on the chemical composition, i.e., tuber dry matter, starch, vitamin C, nitrates and glycoalkaloids were tested. It has been found that the greatest impact on the chemical composition of tubers had the climatic conditions during the growing season and genotype. They affected the contents of all tested components. The place of production affected the contents of dry matter, starch, vitamin C and nitrates. This factor had no effect on the content of glycoalkaloids. The least effect on the chemical tubers composition was in crop production system. It only affected the contents of dry matter, starch and vitamin C. There was no significant effect of this factor on the nitrate and glycoalkaloids content.
文摘The viability of most tomato varieties cultivated in Libya have been tested to infect with potato spindle tuber viroid/potatoes (PSTVd) and its impact on growth and production of some of these varieties, which were mechanically inoculated with Libyan isolate of viroid PSTVd as follows: Vlkato, Sankarh, Lebda, Jasmine, Kenza and Hana. The percent of incidence were 95.95%, 90%, 90.80%, 80% and 20%, respectively. The following varieties have been contagious mechanically with viroid of PSTVd: Vlkato, zahra, Toria, Lebda, Hoda, Farwa, Alkaraz, Naziha, Rim Star and Kartika. The percent of incidence were 95.95%, 85%, 85.80%, 80%, 70.40%, 0.0%, 0.0%, respectively. The varied symptoms of wrinkle, twist, warp, swell the veins of the leaves, dark brown spots formation and a large yellow spots turned into white patches. Also the effect of the Egyptian isolate viroid PSTVd in the growth and production of varieties Jasmine, Lebda, Soberhalim, and treasure No. 185 had been studied, as the average rates of decline in the production of the fruits tomatoes/tomato 43.4% and 17% length of plants, and in the fresh weight and dry root of the sum of 35% and 37% respictively.