江西槟榔芋疫病病原菌鉴定及室内药剂筛选

为明确江西省九江市槟榔芋疫病的病原菌并有针对性地对该病害进行防治,本研究采集具有典型芋疫病症状的芋叶片和叶柄对病原菌进行分离纯化,结合形态学观察、致病性测定及基于ITS、Ypt1和β-tubulin基因联合系统发育分析对该病原菌进行鉴定,并测定了其对7种杀菌剂的敏感性。根据病原菌菌落、卵孢子形态等特征初步鉴定为芋疫霉Phytophthora colocasiae,基于多基因联合系统发育分析结果与形态学结果一致,确定该病原菌为芋疫霉。室内药剂筛选结果表明,23.4%双炔酰菌胺SC对菌丝生长抑制效果最好,EC₅₀为0.006μg/mL;96.8%烯酰吗啉TC、0.3%丁子香酚SL、20%氟吗啉WP、500 g/L氟啶胺SC、97%霜脲氰TC对菌丝生长的抑制效果也较好,EC₅₀介于0.094～1.272μg/mL之间,研究结果可为槟榔芋疫病的化学防治提供参考。     

基于SSR标记的芋头种质资源遗传多样性分析及抗疫病鉴定

为了了解不同来源芋头种质资源的遗传多样性及其对疫病的抗性,本研究从100对SSR引物中筛选出21对多态丰富的SSR引物,并将其用于109份芋头资源的遗传多样性分析,同时采用人工接种芋头疫霉菌的方法对这些资源进性行了抗性评价。结果表明,21对SSR引物在109份芋头资源中共扩增出71个等位基因,变幅在2～4个,平均有效等位基因数3.38;观测杂合度(Ho)变化范围为0.0481～0.8900,平均为0.3483;预期杂合度(He)的变化范围为0.0841～0.6709,平均为0.3794;种群平均Shannon遗传多样性指数为0.6733;遗传距离在0～1之间,平均遗传距离为0.6014。在分支距离为0.49处,可将供试芋头资源分为3个类群。60%以上的抗性资源集中于Ⅰ和Ⅱ类群。本研究可为筛选、鉴定优良芋头种质资源及遗传育种工作提供科学依据。     

重金属铅镉胁迫对芋生长发育和产量的影响

采用盆栽试验研究了0（对照）,500、1 000、1 500、2 000 mg·kg^-1和2 500 mg·kg^-1 6个浓度的铅（Pb）与0（对照）、0.5、1.0、1.5、2.0 mg·kg^-1和2.5 mg·kg^-1 6个浓度的镉（Cd）溶液分别处理土壤对芋生长发育和产量的影响。结果表明,Pb胁迫抑制芋植株的生长,株高最大低于对照25.3%,对芋叶长、叶宽的影响不显著;而Cd浓度在1.0 mg·kg^-1以上显著促进了植株的生长,株高最大高于对照42.1%,最大叶长高于对照60.1%,最大叶宽高于对照60.9%。在1 000 mg·kg^-1和1 500 mg·kg^-1 Pb胁迫下,叶绿素含量显著高于对照,浓度大于1.0 mg·kg^-1时Cd胁迫显著高于对照;Pb胁迫MDA含量同比对照显著增加,最大增加了60.8%,Cd胁迫仅在1.0 mg·kg^-1显著高于对照45.4%。Pb胁迫可溶性糖含量先升后降,1 000 mg·kg^-1时显著高于对照40.6%,Cd胁迫时呈上升趋势,最大高于对照33.5%;Pb胁迫可溶性蛋白呈上升趋势,最大高于对照144.0%,Cd胁迫时先上升后下降,1.5 mg·kg^-1时显著高于对照37.0%;Pb、Cd胁迫均使SOD活性下降,最大下降幅度分别为37.8%和60.0%,使POD和CAT活性增强,POD最大增强幅度分别为119%和78.7%,CAT最大增强幅度分别为298.5%和65.5%。Pb或Cd胁迫均导致芋产量明显下降,最大下降分别为53.6%和56.5%。     

荔浦芋种植过程中土壤养分含量变化及相关性研究

[目的]探索荔浦芋种植过程中土壤养分的含量变化及各养分含量的相互关系,为农业生产提供指导。[方法]在荔浦芋种植过程中的4个时期分别采集土样,并且检测分析。[结果]pH值与土壤有效养分含量密切相关,施加追肥后,土壤pH值明显升高;碱解氮含量在种植前后差异明显;有效磷、有效钾含量随着肥料的施加逐渐增加;微量元素有效态含量在种植过程中也发生了相应的变化。[结论]土壤养分因素之间存在密切联系,各养分含量在种植过程中也发生了相应的变化。适时对土壤养分指标进行检测、分析,才能掌握其变化规律。     

早熟芋头新品种比较试验

为进一步提高常州地区早熟芋头的生产效益,引进早熟芋头品种苏芋10号和苏芋11号,与当地早熟品种建昌早芋进行比较试验.结果表明:苏芋10号生长量最大,株高145.4 cm,显著大于苏芋11号和建昌早芋,最大叶面积也最大,商品子芋平均单个质量达54.69 g;直链淀粉、支链淀粉、粗蛋白含量分别为15.28、78.68、35...     

种植密度对泰兴香荷芋生育·产量·效益的影响

[目的]探讨中等肥力状况的高沙土地区不同种植密度对泰兴香荷芋生育及产量、效益的影响。[方法]在统一垅宽100cm、垅高20cm、垅面宽60～65cm的基础上,试验设6个种植密度处理：种植密度42000株／hm2,株距47．62cm;种植密度47250株/hm2,株距42．33cm;种植密度52500株／hm2,株距38．10cm（CK）;种植密度57750株／hm2,株距34．63cm;种植密度63000株／hm2,株距31．75cm;种植密度68250赫／hm2,株距29．30cm.考查不同生育期的苗情与长势、子孙芋产量、商品芋效益。[结果]63000株／hm2种植密度处理子孙芋产量最高,达25103．70kg,／hm2,商品芋政益为97738．2元／hm2。[结论]中等肥力状况下的高沙土地区泰兴香荷芋大面积种植密度以63000株／hm2为宜。     

凝固型香芋蜂蜜发酵乳的研制

以香芋超微粉为主,辅以紫薯超微粉、蜂蜜、白砂糖为配料,以全脂牛奶为主要原料,经接种酸乳发酵剂制备具有香芋、紫薯特有风味的凝固型发酵乳产品。在单因素试验的基础上,通过正交试验优化发酵乳制备的工艺条件,最后对制成的发酵乳产品进行感官品质评定和理化指标分析。结果表明,发酵乳的最佳工艺参数为：香芋、紫薯超微粉的比例为6∶4,添加量50 g/L,白砂糖和蜂蜜的添加量均为40 g/L,发酵剂最佳接种量为1.8 g/L,最佳发酵时间6 h。在该工艺条件下制成的发酵乳入口酸甜,香芋和紫薯的香味浓郁,营养价值高,其感官指标和理化指标符合国家标准的要求。     

芋头片微波干燥失水特性试验研究

芋头干燥是芋头贮存和深加工过程中重要的一个环节.为此,利用自制微波干燥装置对芋头片进行了微波干燥试验,研究了微波质量比功率、芋头片厚度以及芋头片形状对芋头片干燥失水特性的影响,指出芋头微波干燥过程具有阶段性,得出了微波质量比功率、芋头片厚度和芋头片形状对芋头片干燥失水特性的影响规律,为进一步了解芋头的干燥特性及应用开发提供了一定的依据.     

Effects of alley cropped Calliandra calothyrsus and Cliricidia sipium hedges on weed growth,soil properties,and taro yields in Western Samoa

Field experiments were conducted on a tropical Inceptisol at Apia, Western Samoa to evaluate the effects of alley cropping on soil characteristics, weed populations, and taro yield. Taro yields were compared from Calliandra calothyrsus and Gliricidia sipium alleys, spaced at 4 m, 5 m, and 6 m, and a no tree control. Measurements were made for soil moisture and temperature, weed growth, hedge biomass production, and taro growth and yield. Data was analyzed over 4 consecutive years from 1988 to 1991.Hedge biomass yields ranged from 5.1 to 16.1 t/ha/yr dry weight over the 4 years of the trial, with Calliandra and Gliricidia performing equally well. Biomass yields decreased by about 2 mt/ha with increasing alley width from 4 to 6 m alleys. Weed populations were significantly lower in the 4 m alleys compared to the 5 m, 6 m, and control plots. The 6 m alleys supported the significantly highest weed populations. Soil from alley plots held significantly more water in the 0.3 to 1 bar range than soils from the controls. Four years of mulch application measurably improved soil water holding capacity and bulk density. However, no improvement was seen in nitrogen, phosphorus, potassium, calcium, magnesium and organic carbon content in the alley plots compared to the controls. There was no positive yield effect of alley cropping on taro yield. Yields in the 5 m and 6 m alleys were not significantly different from the control, while the 4 m alleys produce significantly lower yields than the control. Thus, alley cropping did not prove a viable alternative to traditional shifting cultivation after 4 years of continuous cropping, in this trial.     

Isozyme variation in taro (Colocasia esculenta (L.) Schott) from Asia and Oceania

Summary Isozyme variation was studied in 1,417 cultivars and wild forms of taro collected in Asia and Oceania. Seven polymorphic enzyme systems (MDH, IDH, PGI, 6-PGD, ME, SkDH, and ADH) revealed 143 isozyme phenotypes, or zymotypes, each uniquely characterized by the presence or absence of 56 electromorphs. Results showed greater isozyme variation in Asia than in Oceania, with Indonesia being the area of greatest diversity. No correlations were found between zymotypes and morphotypes or ploidy levels (as described by other investigators). Multivariate analyses of the isozyme data indicated that the majority of the Indonesian cultivars were different from the Philippine and Oceanian taro cultivars. Oceanian cultivars constituted a continuum of clusters and are thought to have originated from a narrow genetic base introduced from Indonesia. If taro breeding is to have any future in Oceania, it is important to exchange genotypes to broaden the base of existing breeding programmes.