Effect of Potassium Levels on Growth and Productivity of Potato Varieties

Potato is one of the priority vegetable crops in the highlands of Eritrea growing as a key component in the livelihood systems of farmers. Potato requires a variety of balanced plant mineral nutrients for growth and development without which yield and qualities of tubers are reduced. Potato growers in Eritrea commonly use Di-ammonium Phosphate, Urea and Farmyard manure while potassium fertilizers are overlooked assuming that the soil is developed from K rich parent material and contains sufficient amount of K to support crop growth. However this assumption is based on the result obtained forty-seven years ago. As a result the yield and quality of potato produced is very low as compared with international standards. Therefore the present experiment was conducted to assess the effect of potassium levels on growth and productivity of potato varieties at Hamelmalo Agricultural College, Eritrea. The experiment was conducted in factorial Randomized Complete Block Design with fifteen treatment combinations of three varieties (Ajiba, Zafira and Picasso) and five potassium levels (0, 75, 150, 225 and 300 kg K2O/ha) replicated thrice. The results of the study showed that both variety and potassium had significant effect on growth and yield parameters. Aerial stem number, leaf number per plant and plant height were increased with increasing K levels from 0 to 150 kg while number of days to maturity was increased in the range of 0 - 300 kg K2O/ha. The result also indicated that variety Ajiba treated with 300 kg K2O/ha produced significantly highest tuber weight (1.14 kg) per plant and tuber yield of 49.38 t/ha. The economic analysis result revealed that maximum gross margin 13,665.816 USD/ha was obtained from the application of 300 kg K2O/ha. On the whole, it gives an impression that using potassium fertilizer according to soil requirements will have good influence on growth and tuber yield.

Comparison of Physicochemical,Organoleptic and Nutritional Abilities of Eight Sweet Potato(Ipomoea batatas)Varieties

In Martinique (F.W.I.), biodiversity of vegetable varieties remain unexploited due to public unawareness or supply problems. To further enhance the sweet potato, physicochemical, sensory and nutritional characteristics of eight varieties of sweet potato were established. The eight sweet potatoes cultivars were noticeably diverse with phenotypic, sensory, physicochemical and nutritional characteristics which were very varied. The eight cultivars grown in Martinique were advantageously positioned in relation to the globally identified sweet potato, regarding fibre, starch, potassium, copper, vitamin B1, B3 and B9 contents. Compared to the ordinary potato, Martiniquan sweet potatoes have a much better nutritional potential. Energy value and vitamin C levels were twice as much as in normal potatoes. Martiniquan sweet potatoes cultivars were also richer in minerals and vitamins, with 2.7 times more vitamin B9 and 63 times more beta-carotene than the ordinary potato.

Impact of Implementing 1991 Act of the International Convention for the Protection of New Varieties of Plants in China

The Union for the Protection of New Varieties of Plants is abbreviated as UPOV. The Convention for the Protection of New Varieties of Plants has 1961/1972 Act ,1978 Act and 1991 Act. China is member of UPOV and its regulations of protection of new varieties of plants conform to 1978 Act. At present, there is big debate whether China accedes to 1991 Act. This paper mainly discussed advantages and possibilities that China accedes to 1991 Act, and concluded that it is highly desirable that China should consider acceding to 1991 Act in order to contribute to development of system on protection of new varieties of plants.

Study on Introduction Test of New Varieties of High Quality Conventional Rice in Yangjiang City, China

[Objective]The paper was to seek new varieties of high quality conventional rice suitable for Yangjiang area,Guangdong Province,China.[Method]In 2017,introduction test was performed with seven new varieties of high-quality conventional rice approved by Guangdong Province in recent years,including Huangsilizhan,Guangjingruanzhan,Heliyouzhan,Huahang 48,Limiaozhan,Lvyinzhan,Yuehesimiao,to investigate the main agronomic traits and yield of all varieties tested.[Result]The comprehensive performance of Lvyinzhan,Guangjingruanzhan,Limiaozhan and Huahang 48 was outstanding,showing the characters of good yield,excellent rice quality and strong stress resistance.[Conclusion]Lvyinzhan,Guangjingruanzhan,Limiaozhan and Huahang 48 are suitable for large-scale demonstration and promotion in Yangjiang area.

Study on the Relationship Betweenthe Toxin of Phytophthora infestans(Mont.) de Bary and Resistance of Potato

Plant pathogenic fungi produce mycotoxins which may lead host plants to produce disease symptoms and may have a significant positive role in the course of disease development.The putative Phytophthora infestans toxins were prepared by culturing in liquid medium（60 g rye and 10% tomato juice L-1） for 1 mon at 17℃,filtering through four layers of cheesecloth and being precipitated by ammonium sulfate.The resulted putative toxin solutions were used to study the effects on 3 potato varieties（both leaf and tuber tissues）.The results show that potato leaves and tubers exhibit symptoms similar to the late blight resulted from P.infestans infection.Potato varieties reacting differentially to both the toxin dilutions and toxins produced by different P.infestans isolates suggested the presence of toxin-mediated specificities between potato and P.infestans.Potato leaf and tuber tissues have different and contrary reactions to the toxin.Toxin-mediated specificities are likely present between potato and P.infestans.

Analysis of Genetical Diversity of Some of the Tetraploides Potato Cultivars Grown in Iran

The genetical diversity of potato, Solanum tuberosum was assessed using morphological traits. To verify, how this diversity is distributed among the main potato varieties grown in Iran. A total of eleven potato varieties, Ramose, Sante, Shepody, Marfona, Maradona, Milova, Santana, Boren, Cosima, Granola and Agria, were evaluated under vivo and situ experimental conditions in Isfahan, conditions, Iran. Seven phenological, floral and morphological vegetative aerial descriptors, Growth Rate = CGR, Net Assimilation Rate = NAR, Leaf Area Duration = LAD, Leaf Area Ratio = LAR and specific Leaf Area = SLA were recorded. The descriptors were evaluated by SAS Software and their means comparison by DMRT test. Certain defined groups were observed, indicating that the diversity of the cultivars are structured with a considerable morphological variation in between the varieties with a very high significant growth indices.

Screening of Extraction Methods for Protein from Potato Tubers

[Objectives]This study was conducted to screen different extraction methods for protein from potato tubers.[Methods]The bud eye,lateral and pith parts of Qingshu 168 and Kexin 1 were used as test materials,and were extracted by acetone extraction,trichloroacetic acid(TCA)extraction,salt extraction,alcohol extraction and phenol extraction,respectively.The protein contents of different parts were determined by spectrophotometry.A 2-factor randomized block design was used to study the effects of varieties,extraction methods,sampling parts and combinations of different factors on protein content.[Results]The protein contents of different varieties were different,and Qingshu 168 was significantly higher than Kexin 1(P<0.05),reaching 128.0 mg/L.The protein contents obtained by different extraction methods were different.Acetone extraction,salt extraction and TCA extraction showed no significant differences in the protein content,but they were significantly higher than phenol extraction and alcohol extraction(P<0.05).The protein contents obtained by the former three were in the range of153.3-159.7 mg/L.The protein content in the bud eye part of potato tubers was significantly higher than those in the lateral and pith parts(P<0.05),reaching140.7 mg/L.There were significant differences among different combinations of varieties,extraction methods and sampling parts(P<0.05).The comprehensive comparison showed that the salt extraction method was suitable for the bud eye part of Qingshu 168,and the TCA extraction method was suitable for the bud eye part of Kexin No.1.[Conclusions]This study provides a reference for potato protein extraction and further research.

Effect of Variety and Size of Stem Cutting on Flesh Root Yield and Yield Components of Sweet Potato

Sweet potato is an important food crop which contributes to food security. Storage roots are stored in the ground and harvested when needed. In coastal Kenya, the production of the crop is limited by lack of adaptable varieties and shortage of planting materials at the onset of long rains. The prevailing prices of sweet potato vines for planting present a hindrance for sweet potato cultivation culminating to low acreages by farmers. This study was carried out during the long rains of 2011 to 2013 to determine the effect of variety and size of sweet potato cutting on root yield. Four sweet potato varieties were planted under four stem cutting sizes of four, six, eight and 10 nodes. The four varieties were K135, Bungoma, SPK004 and Mtwapa 8 （check）. The experimental design was a split plot with varieties assigned to main plots and cutting sizes to sub-plots. The number of roots per plant for Bungoma variety was significantly （P 〈 0.05） less than that for the check, and variety K135 showed significantly （P 〈 0.05） higher number of marketable root per plant than the check. The same trend was observed for root yield per hectare. The check variety had the highest percent of dry matter and was significantly higher than that of SPK004 and Bungoma varieties. There were no significant （P 〈 0.05） differences among the stem cutting sizes as regards to number of roots per plant, number of marketable root per plant and percent of dry matter. The cutting size of six nodes gave similar root yield as the recommended eight nodes, and therefore farmers can adopt shorter vines than the recommended, hence saving on the cost of planting materials.

Analysis of Yield and Disease Resistance Traits of New Winter Rapeseed Varieties over the Past Twenty Years in China

Based on the results of the national regional trail for winter rapeseed in four groups,including the upper reaches,middle reaches and lower reaches of Yangtze River and Huang-Huai region in the past twenty years,new varieties of winter rapeseed showed upward trend in average yield,the yield level in Huang-huai group was higher than other groups.The changes of average effective pods per plant were not significant in any group,but the number of grain per pod and 1 000-grain weight showed increase trend.However,the increment of grains per pod in three Yangtze River groups was higher than that in Huang-Huai River group,while the increment of 1 000-grain weight was just opposite.The incidence rate of Sclerotinia sclerotiorum and viral disease in new varieties of winter rapeseed obviously decreased,and the incidence rate of S.sclerotiorum decreased lower than 5%.Genetic improvement for winter rapeseed should be focus on the number of grain per pod and 1 000-grain weight in the future,and yield level of new varieties in all four groups is expected to increase.

Brave New Potato

By the time Ireland’s terrible potato famine of 1845 had run its course, 1 million people had starved to death. Survivors recalled seeing people dying by the roadside, their mouths stuffed with grass. The cause of the suffering was a virulent fungus known as late blight disease, or Phytophthora infestans,

A New Combination and Two Varieties of Polystigmate Gomphonema (Gomphonemaceae Bacillariophyta) from Heilongjiang Province, China

The authors discribed a new polystigmate combination, Gomphonema turris Ehr. var. okamurae (Skv.) Fan et Bao.comb.nov., and two new varieties, Gomphonema turris Ehr. var. latum Fan et Wang. var. nov. and Gomphonema acuminatum var. obtusum Fan et Bao, var. nov., that were distinguished by frustule morphology under LM. The samples were collected from freshwater of Heilongjiang Province, China.

Characterization of QTL for unique agronomic traits of new-plant-type rice varieties using introgression lines of IR64

To enhance the yield potential of an elite indica rice cultivar,an introgression(BC_3-derived) line of IR64,YTH288,was developed using a new-plant-type cultivar,IR66215-44-2-3,as a donor parent.YTH288 has agronomically valuable characteristics such as large panicles,few unproductive tillers,and large leaves inherited from NPT.To identify the genetic basis of these traits,we used 167 F_2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits:days to heading(DTH),culm length(CL),flag leaf length(FLL),flag leaf width(FLW),and filled spikelet number per panicle(FSN).Six putative QTL were detected:four on chromosome4(for CL,FLL,FLW,and FSN) and two on chromosome 2(for DTH and FLL).All QTL with the IR66215-44-2-3 allele,except that for FLL on chromosome 2,had positive effects on each trait.To confirm the effects of these putative QTL,we developed NILs with the IR64 genetic background by marker-assisted selection.We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4.Additionally,four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropic To enhance the yield potential of an elite indica rice cultivar, an introgression(BC3-derived) line of IR64, YTH288, was developed using a new-plant-type cultivar,IR66215-44-2-3, as a donor parent. YTH288 has agronomically valuable characteristics such as large panicles, few unproductive tillers, and large leaves inherited from NPT.To identify the genetic basis of these traits, we used 167 F2 plants derived from a cross between IR64 and YTH288 to conduct QTL analysis for five agronomic traits: days to heading(DTH), culm length(CL), flag leaf length(FLL), flag leaf width(FLW), and filled spikelet number per panicle(FSN). Six putative QTL were detected: four on chromosome4(for CL, FLL, FLW, and FSN) and two on chromosome 2(for DTH and FLL). All QTL with the IR66215-44-2-3 allele, except that for FLL on chromosome 2, had positive effects on each trait. To confirm the effects of these putative QTL, we developed NILs with the IR64 genetic background by marker-assisted selection. We observed significant differences in several agronomic traits between IR64 and NILs that carried these QTL on chromosomes2 and 4. Additionally, four IR64-NILs carrying chromosomal segments derived from different NPT varieties on the long arm of chromosome 4 exhibited similar pleiotropiceffects for unique agronomic traits. These NILs can be used as research materials for studying each trait and as breeding materials for yield improvement of indica rice cultivars.

Boehmeria nivea var. strigosa (Urticaceae), a new variety from Southwest China

Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly characterized by its green abaxial leaf blade,partly connate stipules,and densely patent strigose hairs on stems and potioles.The phylogenetic analysis based on rbc L,nrDNA and rbc L+nrDNA datasets,revealed that all individuals of B.nivea var.strigosa formed a monophyletic group.The conservation status of B.nivea var.strigosa is assessed as“Near Threatened”(NT)according to IUCN evaluation criteria.The discovery of this new variety is not only crucial for the taxonomy of ramie,but also provides reference for the exploration and utilization of ramie.

Farmers' Privilege under the Protection of New Plant Varieties

This paper studies farmers'privilege under the protection of new plant varieties,and points out that farmers'privilege is given to balance interests of plant breeders and relevant public.Based on this,it analyzes shortcomings of farmers'privilege regulations,and puts forward that it is required to improve farmers'privilege regulations in subjects,objects and contents of rights on the basis of learning from advanced legislation experience of foreign countries,and build the interest sharing mechanism between breeders and farmers.

Correlation and Cluster Analysis on the Quality Characters of New Middle-ripe Japonica Rice Varieties in Jiangsu Province

[ Objective] This study aimed to analyze the quality characteristics of the new middle-ripejapon/ca rico varieties in Jiangsu Province. [ Method] Four- teen new rice varieties included in the Middle-ripe Japon/ca Rice Regional Test in 2011 were selected as the materials. Correlation analysis and cluster analysis were carried out on their quality traits. [Result] The rice cultivars possessed stable characteristics, which were difficult to be further improved. In addition, their quality traits had extremely complicated relationships, and the differences were significant between different groups. [ Conclusion] This study will provide reference for improving the quality traits of japonica rice.

New Varieties of Populus tomentosa Carr. and Breeding Techniques

The main morphological characteristics, producing area and growth characteristics of sixteen new varieties of Chinese white poplar （Populus tomentosa Carr. ） are reported, aiming at providing reference for breeding and extension of new varieties.

Comprehensive Evaluation of Flower Border Application Value of New and Superior Plants in Hefei Area

An analytic hierarchy process(AHP)was employed to assess the applicability of 18 new and superior varieties of flowers in Hefei City flower border applications.A total of 12 indicators were selected from three distinct aspects of adaptability,ornamental characteristics and use traits,in order to establish a comprehensive evaluation model.The results demonstrate that grade I(J≥2.685)exhibits excellent application value,encompassing six species of plants,such asHydrangeamacrophylla‘Endless Summer’;grade II(2.684≤J≤2.420)is also of notable application value,encompassing five species of plants,such asCallistemonrigidus;grade III(2.419≤J≤2.615)is of average application value,including five species of plants,such asCrocosmiacrocosmiflora;grade IV(J≤2.16)is of relatively poor application value.The evaluation results may be utilized as a theoretical reference for the promotion of new and superior varieties in the flower border of Hefei.

NEW VARIETIES AND LINES

Ⅱ-you 92: a new hybrid rice for late seasonⅡ-you 92 is an indica hybrid rice that was developed by Jinhua Agri Res Inst, Zhejiang Province.Ⅱ-you 92 has a suitable growth duration of 122-125 d as double-cropping late season rice, 3-4 dshorter than that of Shanyou 64 and 6-7 d shorter than Shanyou 10. It has a compact plant type, high tiller-ing ability and plant height of 85-90 cn. A number of 3.4-3.6 million effective panicles per ha can be

NEW VARIETIES AND LINES

Qixiuzhan 3:a new high-yielding, good-quality indica rice varietyBy crossing Qishanzhan with Xinxiu 299, a new variety Qixiuzhan 3 was developed by the Rice Res Inst ofGuangdong Acad of Agri Sci.Being planted in the early season, this variety belongs to mid-late-maturity rice, with the same ma-

New technique for identifying varieties resistance to rice blast

After 8 yrs lab experiments and field tests, an advanced technique for identifying varieties resistance to rice blast was developed by a research group in Plant Protection Institute, Zhejiang Academy of Agricultural Sciences. With this technique, the inoculum was prepared on a maize-rice-straw-agar media which was suitable for sporulation of most rice blast pathogen isolates. To avoid possible virulence variation during the vegetative growth, the conidia were harvested and preserved for later different sets of resistance evaluation tests. A simple and precise new method—smear inoculation was used for infection. The experi-