Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

Comparative Study on the Efficacies of 11 Chemical Agents against Taro Soft Rot Caused by Pectobacterium aroidearum

[Objective]The paper was to screen the effective agents for effectively controlling the occurrence and prevalence of taro soft rot.[Method]The fungicidal effects of 11 fungicides on taro soft rot were determined by inhibition zone method.[Result]0.3%Tetramycin,25%bromothalonil,3%Zhongshengmycin and 30%zinc thiazole had better antifungal effect on Pectobacterium aroidearum at recommended concentration.The indoor toxicity of four fungicides showed that the EC50 of 0.3%tetramycin AS was the smallest of 0.6μg/mL,indicating that tetramycin had the largest toxicity and the best inhibitory effect against P.aroidearum;followed by 25%bromothalonil EC and 3%Zhongshengmycin WP,with the EC_(50) of 2.57 and 97.72μg/mL,respectively;the inhibitory effect of 30%zinc thiazole SC against P.aroidearum was the poorest.[Conclusion]The study provides a reference for screening out new and efficient chemical agents against taro soft rot.

Analysis of Climate Suitability of Lipu Taro Planting in Lipu County

Based on the analysis of planting situation, climatic characteristics and field management technology of Lipu taro in each growth period, climate suitability of Lipu taro was studied. The results show that temperature affects the growth of Upu taro most greatly, and sunshine hours and precipitation also influence it obviously. In order to make Lipu taro develop well, it is necessary to utilize climate resources rationally and strengthen the control of diseases and insect pests and field management.

Effect of Different Concentrations of Orange Juice for in Vitro Regeneration and Multiplication of Cocoyam (Taro)

Taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium) are commonly referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Traditionally, cocoyams are vegetatively propagated from tuber fragments, a practice that encourages pathogen distribution. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. In this study different concentrations of ripped sweet orange (Citrus sinensis) juice were screened for regeneration and multiplication of 2 months old in vitro cocoyam shoot explants. Among the concentrations, maximum numbers of roots (37 ± 5) were observed in Murashige and Skoog (MS) medium supplemented with 10% orange juice after 8 weeks in culture compared to 16 ± 4 (roots) observed in the control medium. On shoot multiplicity, 16 ± 3 shoots were induced in the control medium in contrast to 12 ± 0.8 shoots in the MS medium supplemented with 10% orange juice after 8 weeks of culture. Higher concentrations (25% and 35%) of the orange juice supplemented medium resulted in concomitant inhibition of all the growth parameters. The study successfully established that ripped orange juice could substitute the use of conventional growth hormones cytokinins (BAP) and auxins (NAA) in in vitro regeneration and rapid multiplication of cocoyam shoot explants.

Effect of Processing on the Oxalate and Calcium Concentrations of Two Local Dishes, Cơm Hến and Canh Chua Bạc Hà, Prepared from Taro Stems

Stems of sweet taro (Colocasia esculenta) grown in Thua Thien HuếProvince in Vietnam and were used as an ingredient to prepare two local dishes, Cơm Hến and Canh Chua Bạc Hà. This study investigated the effect of simple processing treatments used to prepare these popular dishes on the total, soluble and insoluble oxalate and calcium contents of the taro stems. Raw stems were used to prepare Cơm Hến. Three treatments, removing the skin then washing and slicing, slicing and washing, or slicing and then allowing the stems to wilt overnight were compared to the whole raw stems with the skin retained. Overall, processing the stems reduced the soluble oxalate contents by a mean of 8% when compared with the original raw stems. The mean total calcium bound in the insoluble oxalate fraction of the three processing treatments was 43.3% ± 2.0%. Canh Chua Bạc Hà was prepared by boiling peeled taro stems. In this experiment the peeled stems were boiled for 10, 15 and 20 min and this resulted in 63.4%, 74.5% and 76.6% reductions in soluble oxalate content, respectively, when compared to the original peeled stems. Boiling for 20 min was the most effective way to reduce both the total and soluble oxalate contents of the stems. 39% of the total calcium in the raw taro stems was bound to the insoluble oxalate fraction and this was reduced to a mean of 17.2% ± 2.6% by the three cooking treatments.

Effect of Pre-Gelatinization Conditions on the Total Oxalate Content and Techno-Functional Properties of Taro (Colocasia esculenta) Flour

Like most roots and tubers, taro (Colocasia esculenta) corms have a short shelf-life due to the high moisture content, which aggravates their post-harvest losses. They also contain high amounts of calcium oxalates, limiting their use in food applications. To help add value and diversify the use of taro corms as well as curb food losses, various strategies have been proposed, such processing of the corms into flour. This study aimed at evaluating the total oxalate content and techno-functional properties of taro flour as affected by the pre-gelatinization conditions (i.e., method and time). Pre-gelatinized taro flour was prepared by subjecting peeled and cleaned taro corms to roasting (190°C), boiling (100°C), and steaming (100°C) for 10 min, 20 min and 30 min, respectively, for each method, followed by drying at 55°C and milling. Generally, all the properties of flour were significantly affected by the pre-gelatinization conditions (P 0.05). The total oxalate content of the pre-gelatinized taro flour ranged from 33.26 to 76.90 mg/100g. Pre-gelatinization by boiling significantly reduced the oxalate content (56.7%), while roasting resulted in the least reduction (36.2%). The flour colour i.e. L*, hue, and chroma ranged from 38.47° - 70.30°, 42.64° - 69.43°, and 7.78° - 10.58°, respectively. Roasting resulted in flour with the largest L* (70.30°) and hue angle (69.43°). Boiling also resulted in flour with the highest bulk density (BD) (0.86 g/cm3) and the lowest water solubility index (WSI) (9.39%). Steamed flour had the highest water absorption index (WAI) (3.81 g/g), water holding capacity (WHC) (4.59 g/g), and swelling capacity (SC) (4.86 g/g). This study shows that pre-gelatinization (i.e. by boiling, steaming or roasting) significantly affects the total oxalate content and techno-functional properties of taro flour, which in turn influences its use in other food applications thus increasing the utilization and production of taro simultaneously.

Control Effect and Application Technology of Mandipropamid on Red Taro Blight

The field experiment results showed that 250 g/l mandipropamid suspension had good control effect on red taro blight,and the 1∶1500 suspension was applied twice continuously during the early period( June 25) and culmination period( July 12) of taro blight; the control effect 23 d after the last application reached 79. 28%,significantly better than that of conventional pesticide,and it was safe,so it had good prospects for the development and application in production.

Genetic Diversity of Taro Landraces from Côte d’Ivoire Based on Qualitative Traits of Leaves

Taro is an important crop species in Côte d’Ivoire. It is cultivated for its tubers and leaves. But its knowledge and genetic diversity and differentiation are very weakly documented. Several morphological types are found in rural area, but their identification is not very clear, and their agronomic potentiality is underexploited. In this context we initiated a survey and collected 213 accessions from 14 growing regions of Côte d’Ivoire. The diversity was evaluated based on seven qualitative traits of leaves (Shape of the base of the leaf, Predominant position (shape) of the leaf blade surface, Margin of the leaf blade, Leaf blade variegation, Profile of the petiolar junction, Shape of the leaf sheath, Shape of the appendix) during an experimentation conducted in rural area. The objective of this study was to characterize the collection of taros collected in different geographical zones of Côte d’Ivoire and identify the genera cultivated. Results of our study indicated that excepted margin of the leaf blade all traits are very discriminant. Several variants were observed for each of traits. According to observations and statistics analysis accessions were separated into two main groups. The characteristics of these groups indicate that taro cultivated in Côte d’Ivoire could belong to two genera: Xanthosoma and Colocasia.

Evaluation of Different Substrates Compositions for Acclimatization of Tissue Culture Taro Plantlets in a Propagator

Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.

Fluorine in Water and Dental Fluorosis in a Community of Queretaro State Mexico

The community La Llave, Queretaro State, Mexico, has not been identified by the sanitary authorities as living in a hazard area related to dental fluorosis. However;a high concentration of fluoride is found in their drinking water causing them dental fluorosis. Physical-chemical analysis was carried out in the groundwater sources to determine the prevalence of dental fluorosis risk and caries accordingly to criteria of The World Health Organization, and 154 school children of ages 10 to 13 years were examined. As a result, 1.9 mg/L of fluorine concentration in drinking water was obtained;dental fluorosis presence was detected in the school children with an incidence of about 98%, in 47% of cases severe fluorosis with a dental caries index of 3.06 was traced. The groundwater sources in La Llave community contains fluorine above the limits dictated by Mexican regulations, producing serious repercussions on the health of school children, with an unnaturally high incidence of dental fluorosis.

Preliminary Assessment of Genetic Diversity in Three Taro （Colocasia esculenta L, Schott） Landraces Using Agro-morphological and SSR DNA Characterisation

Taro （Colocasia esculenta L. Schott） is an important underutilised crop in South Africa, East Africa and Indonesia. Three taro landraces, namely, Dumbe Lomfula （wild）, KwaNgwanase and Umbumbulu, were collected from two locations in KwaZulu-Natal （KZN）, South Africa, and planted at two locations, Pietermaritzburg （KZN） and Roodeplaat, Pretoria. Ago-morphological characterisation of vegetative and corm characteristics were done four months after planting and at harvest, respectively. Sampling for DNA fingerprinting using five SSR primers was done using leaf material four months after planting. Agro-morphological characterisation was useful in showing differences between the wild landrace and the two cultivated landraces, as well as identification of dasheen and eddoe types. SSR primer characterisation showed that despite significant morphological difference, the wild Dumbe Lomfula and Umbumbulu landraces were closely related but different from the KwaNgwanase landrace. Although landraces showed great morphological variation, this did not necessarily imply genetic variation. It is concluded that SSR primers are more useful for characterising taro landraces.

Molecular Detection of Phytophthora colocasiae of Taro Leaf Blight Based on PCR

The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmission and spread of the causal organism of taro leaf blight in taro planting regions.The samples were used to extract total DNA and to be detected by PCR with P.colocasiae specific primer pairs PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.Distinct fragments of about 200 bp and 240 bp were amplified by PCR using primers PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.The analysis of the nucleotide sequence of the PCR products were found to be 99% identical to sequence of RAS-related protein (Ypt1) and phospho-ribosylanthranilate isomerase (TRP1) in P.colocasiae,respectively.It is concluded that rapid and sensitive developed PCR assay for detection of P.colocasiae could be used in routine diagnosis and aid in management practices to mitigate taro leaf blight.

干旱胁迫对芋球茎淀粉和蔗糖代谢通路相关基因表达的影响

[目的]探究芋球茎响应干旱胁迫的分子机制,特别是干旱胁迫对淀粉和蔗糖代谢通路相关基因表达的影响,为耐旱品种选育提供依据。[方法]以荔浦芋1号为试验材料,对干旱胁迫下的芋球茎进行转录组测序,对获得的差异表达基因进行GO和KEGG富集分析,进一步筛选与淀粉和蔗糖代谢通路相关的酶基因,并分析这些酶基因在干旱胁迫下的表达模式。[结果]芋球茎在干旱胁迫下筛选到差异表达基因1983个,其中上调表达基因373个,下调表达基因1610个。GO富集分析显示,差异表达基因在生物过程富集最多的是细胞过程和代谢过程,在细胞组分富集最多的是细胞解剖实体,在分子功能富集最多的催化活性和结合。KEGG富集分析显示,富集最多的通路分别是代谢通路、氮素代谢通路、抗坏血酸和醛酸代谢通路。对淀粉和蔗糖代谢通路的差异表达基因进行统计,共筛选到26个差异表达基因,涉及11种酶,其中上调表达基因5个,下调表达基因21个。在干旱胁迫下,淀粉合成酶、己糖激酶、果糖激酶、UTP-葡萄糖-1-磷酸盐尿苷酸转移酶、α-淀粉酶、内切葡聚糖酶、β-葡萄糖苷酶和β-呋喃果糖苷酶的基因下调表达;UDP-葡萄糖磷酸水解酶和海藻-6-磷酸合成/磷酸酶的基因上调表达;蔗糖合成酶和β-呋喃果糖苷酶的基因既有上调表达,也有下调表达。[结论]淀粉和蔗糖代谢通路相关基因的表达受到干旱胁迫的影响。调控淀粉代谢和海藻糖生物合成相关基因下调表达,而调控蔗糖代谢相关基因既有上调表达,也有下调表达。

壳寡糖浸种对低温下江西铅山红芽芋脱毒试管芋萌发及生理代谢的影响

江西铅山红芽芋脱毒试管芋一般在1月至2月上旬晴天播种,“倒春寒”等低温胁迫会导致早播的江西铅山红芽芋脱毒试管芋生长缓慢,出苗周期变长,严重时会造成烂种死亡,出苗率降低,影响其产量。为提高播种期江西铅山红芽芋脱毒试管芋抗寒性,该研究利用植物组织培养和植物生理学的方法测定了壳寡糖浸种后低温下江西铅山红芽芋脱毒试管芋的萌发及其相关生理指标。结果表明:200~250 mg/L壳寡糖浸种可显著促进低温下江西铅山红芽芋脱毒试管芋的萌发。与低温对照相比,当浸种浓度为200 mg/L时,在内源激素方面,有利于低温下江西铅山红芽芋脱毒试管芋萌发过程中赤霉素、玉米素核苷、多胺和茉莉酸的积累,而不利于生长素和脱落酸的积累;在抗氧化方面,提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,降低了丙二醛和过氧化氢的含量;在渗透调节方面,有利于可溶性糖、可溶性蛋白、脯氨酸的积累;在代谢关键酶方面,可提高脂肪酶、蛋白酶和α-淀粉酶活性以及三磷酸腺苷含量。因此,200 mg/L壳寡糖可以调控低温下江西铅山红芽芋脱毒试管芋内源植物激素和渗透调节物质含量、抗氧化酶和代谢关键酶活性,促进其在低温下的萌发。

含紫薯花青素的槟榔芋淀粉薄膜性能及其应用

开发含紫薯花青素(PSPA)并可生物降解的槟榔芋淀粉薄膜(TSF),并研究其光学性能、厚度、含水率、水溶性、颜色、总酚含量、抗氧化活性、红外光谱和微观结构等性能,初步探讨TSF对鲜切莴笋、鱼肉和猪肉储存过程中新鲜度的指示作用。研究表明TSF的紫外-可见光谱和PSPA溶液的光谱变化规律是一致的,表明PSPA与槟榔芋淀粉具有良好的成膜机制。TSF厚度适中,含水率为39.17%,水溶性为36.93%;TSF的DPPH清除率达到94%,表明TSF的抗氧化活性高。将TSF应用于鲜切莴笋、鱼肉和猪肉的新鲜度监测,TSF先呈现淡紫色,随着时间推移,鲜切莴笋、鱼肉和猪肉逐渐腐败变质,48 h后,TSF在莴笋中呈现蓝紫色、猪肉中呈现浅绿色、鱼肉中呈现淡黄色。

一种槟榔芋疫病病原菌的分离鉴定与生物学特性

为提高槟榔芋产量和品质,探究槟榔芋疫病病原菌的生物学特性,从福鼎槟榔芋疫病发病叶片的病斑中分离病原真菌,得到可疑菌株T5-1.经Koch’s法则证病、形态学和测序鉴定,初步证明其属于小孢根霉菌(Rhizopus microsporus).生物学特性研究发现:其菌落正面为灰白色,反面为黄褐色,菌丝毛绒状延展,边缘整齐,黑色孢子囊.实验结果表明,该病原菌在pH=5~9的培养基上均能生长,最适为pH=6,培养温度在4~45℃时均能生长,最适温度为40℃.

紫薯香芋果冻的研制

以优质的紫薯和香芋为主要原料,经调配、混合熬煮、过滤、杀菌等工艺流程,研制出一种具有浓郁紫薯味和香芋味的果冻。以感官评价为评分标准,分析紫薯汁与香芋汁的配比,白砂糖、柠檬酸及复配胶的添加量对果冻品质的影响。通过正交试验确定紫薯香芋果冻的最佳配方。结果表明,影响果冻感官品质因素的主次顺序为柠檬酸添加量、紫薯汁与香芋汁的配比、白砂糖添加量、复配胶添加量,并且紫薯香芋果冻的最优配方为紫薯汁与香芋汁的配比1∶1,白砂糖9%,柠檬酸0.2%,复配胶1.5%。经此配方制出的果冻色泽均匀一致、口感爽滑、酸甜可口、细腻柔软,感官评分为86.6分,pH值为4.04,可溶性固形物含量为15.28%。

L-抗坏血酸联合超声处理对鲜切芋艿贮藏品质的影响

为探究L-抗坏血酸(L-ascorbic acid,AA)联合超声(ultrasound,US)(AS)处理对鲜切芋艿片贮藏品质的影响,本实验以永定六月红芋为材料,采用质量分数为2%的AA溶液浸泡15 min后,进行US(53 kHz、400 W、10 min)处理,测定贮藏期间鲜切芋艿感官品质及褐变相关酶等指标。结果表明:与对照组相比,AS处理可以降低鲜切芋艿的失水率,维持较高的硬度,延缓褐变指数升高,降低细胞膜通透性,抑制丙二醛含量累积,抑制表面微生物繁殖,从而维持鲜切芋艿较高的感官品质;与对照组相比,贮藏期间AS处理组还能维持较高的过氧化氢酶、超氧化物歧化酶活性,降低过氧化物酶、多酚氧化酶和苯丙氨酸解氨酶活性,抑制酚类物质消耗速率,并减缓淀粉、可溶性蛋白、可溶性固形物等营养物质的流失速率,抑制可溶性醌的积累,延缓风味劣变。上述结果表明,AS处理能够保持鲜切芋艿较好的贮藏品质。

L-抗坏血酸联合超声处理鲜切芋艿的最佳条件

【目的】确定L-抗坏血酸(L-ascorbic acid,AA)联合超声(ultrasound,US)处理鲜切‘六月红芋’的最佳条件,并探究其保鲜效果。【方法】以永定‘六月红芋’为试材,通过对比自来水、纯水、去离子水、9%蔗糖溶液、1%碳酸钠溶液、1%氯化钠溶液、1%AA溶液以及不同有效氯质量浓度(20、40、60、80 mg/L)的微酸性电解水等11种保鲜护色液,筛选出对鲜切‘六月红芋’保鲜效果最佳的护色液。随后,进行AA与乙醇复配液处理,实验结果显示,AA单独使用的保鲜效果更佳。通过测定褐变度、硬度、pH值、相对电导率及感官评价得分等指标,进一步深入研究AA与US联合(AS)处理对鲜切‘六月红芋’贮藏品质的影响,以明确AS处理对鲜切‘六月红芋’的保鲜效果。【结果】在AA浓度为2%、浸泡时间为15 min、US处理时间为10 min、US频率为53 kHz、US功率为400 W的条件下,鲜切‘六月红芋’的感官品质最好。AS处理有效抑制褐变度的增加,维持酸度稳定性,减缓硬度的下降,保持细胞膜的完整性和较高的感官评分,这些参数为AS处理鲜切‘六月红芋’的最佳条件。【结论】在不同浸泡液中筛选得到AA为最佳护色液,并确定AS处理鲜切芋艿的最佳条件。AS处理能够显著提高鲜切‘六月红芋’的保鲜效果。

多维度解析干燥方式对荔浦芋品质特性的影响

【目的】从多维度解析不同干燥方式处理的荔浦芋品质差异性,为定向筛选荔浦芋的干燥加工方式提供理论依据。【方法】以条状和片状的荔浦芋为试材,采用热风干燥、热泵干燥、真空冷冻干燥和微波干燥4种干燥方式进行处理,对其品质特性、流变特性及微观结构进行测定,比较不同干燥方式的干燥效果差异。【结果】微波干燥处理的条状荔浦芋多糖含量最高,为1.178%,片状则表现为真空冷冻干燥处理的多糖含量最高,为0.976%,且真空冷冻干燥方式对不同物料形态多糖的含量影响小;不同干燥方式处理荔浦芋条、片的含水量和支链淀粉含量变化趋势一致,以真空冷冻干燥处理的芋头含水量和支链淀粉含量最低,其中芋头片含水量和支链淀粉含量分别为4.455%和1.920 mg/g,芋头条分别为3.395%和2.338 mg/g。4种干燥方式处理下的荔浦芋体系均表现为典型的剪切稀化行为,同一剪切速率下表观黏度和剪切应力均区别明显,从大到小依次为微波干燥>真空冷冻干燥>热泵干燥>热风干燥;条状芋头的表观黏度总体随多糖含量的增加而增加。真空冷冻干燥处理下的荔浦芋全粉微观上表现为光滑、完整的球状颗粒,而其他3种干燥方式处理的全粉在结构上均出现不同程度的破损、塌陷。【结论】真空冷冻干燥处理的荔浦芋含水量和支链淀粉含量低,且能最好地维持荔浦芋样品原始形状,干燥效果最优。