不同药剂对甘薯疮痂病的防控效果

为有效防控甘薯疮痂病,试用甲基托布津可湿性粉剂、多菌灵可湿性粉剂、苯菌灵可湿性粉剂、代森锰锌可湿性粉剂、硫酸链霉素可溶性粉剂、噻菌铜悬浮剂和硫磺?多菌灵悬浮剂7种药剂对甘薯疮痂病的防控效果进行对比试验。结果表明,50%硫磺?多菌灵悬浮剂500倍液、50%多菌灵可湿性粉剂400倍液和70%甲基托布津可湿性粉剂600倍液对甘薯疮痂病的防控效果较好。     

基因型和栽插密度对甘薯农艺性状及结薯习性的影响

以6个优质食用甘薯品种为研究对象,采用两因素完全随机设计方法,探讨不同基因型和栽插密度对甘薯主要农艺性状、结薯性及产量的影响.结果表明,茎粗、最长蔓长和蔓薯比(T/R)在不同基因型间差异显著,T/R在不同栽插密度下差异显著,基部分枝随栽插密度增高而降低.单株鲜薯重、薯块烘干率和单位面积鲜薯产量等产量性状,在基因型、基因型×密度间均表现出显著或极显著差异,单位鲜薯重随栽插密度增加逐渐降低,单位面积鲜薯产量则随栽插密度升高而增加.该试验6个甘薯品种的结薯性均表现出大薯数＜中薯数＜小薯数,且不同基因型大薯率呈极显著差异;大薯和商品薯数、大薯率随栽插密度的升高而降低,中、小薯数,中、小薯率在不同栽插密度间无显著差异.相关性分析表明,基部分枝和单株鲜薯重呈显著正相关;薯块烘干率与茎粗呈显著正相关,与最长蔓长呈显著负相关;单位面积鲜薯产量与单株鲜薯重呈显著正相关,与烘干率成显著负相关;大薯率与大薯数、单株鲜薯重呈极显著正相关,与中、小薯率呈极显著负相关.本试验表明,栽插密度为7.5×104株/hm2,6个甘薯品种的商品薯数和单位面积鲜薯产量均达最高.     

Persistence of soil and foliar azadirachtin treatments to control sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) on tomatoes under controlled (laboratory) and field (netted greenhouse) conditions in the humid tropics

Persistence of neem-based products against sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) was tested in air conditioned rearing rooms and tropical netted greenhouses (GHs). Two commercial neem products, NeemAzal^®-T/S (1% azadirachtin) and NeemAzal^®-U (17% azadirachtin), were used. Foliar application, under room conditions at dose-rates of 7 and 10 ml NeemAzal^®-T/S, induced an immature mortality of 32 and 44%, respectively, whereas 7 days post-application, under GH conditions, mortality rates declined to 5 and 7%, respectively. This result indicated rapid dissipation of the active ingredients. However, systemic application by soil drenching resulted in more stable effects under both laboratory and GH conditions. After soil drenching with solutions of 3.0 g NeemAzal^®-U until 7-day, immature mortality declined from 88% for the first day to almost half (45%) by day-7 in the GH, and from 90% on first day to 64% by day-7 under laboratory condition. Similar response trends for B. tabaci were obtained for other parameters such as adult colonisation, egg deposition, and egg hatch. The loss of efficiency of the neem products was clearly related to dose-rate, methods of application, and environment (temperature and UV). Soil application is therefore, a convenient approach to achieve high efficiency and persistence with neem products under the conditions in tropical GH environments for whitefly management.     

甘薯高光效育种技术探讨

通过对本课题组近年来所选育的高光效类型系列品种(品系)的特征特性进行综合分析,探讨了甘薯高光效育种技术。结果显示:甘薯高光效育种的开展非常必要且切实可行,其育种目标为在杂交后代早期选拔减小种植密度,使其杂交后代无性系充分发育,减少株间和行间竞争,并且应主要鉴定质量性状;另外甘薯高光效品种应具备的优良性状为短蔓多分枝,株型半直立,经济系数高,同时具备优质、抗病、早熟等优良性状。高光效品种具有更高的增产潜力和实现机械化收获的特性,容易被企业和种植户所接受,在今后育种中我们应当加大该类型品种的选育和开发。     

Analysis of Genetic Diversity Among Sweetpotato Landraces in China

Genetic diversity of 48 sweetpotato landraces randomly sampled from Anhui,Fujian, Henan and Guangdong provinces in China was analyzed using RAPD, ISSR and AFLP markers. Thirty RAPD primers, 14 ISSR primers and 9 AFLP primer pairs generated 227, 249 and 260 polymorphic bands, respectively. AFLP markers were better than RAPD and ISSR markers in terms of the number of polymorphic bands detected and the experimental stability. These three molecular markers revealed the similar results that Chinese landraces exhibited a high level of genetic diversity, and the genetic variation of Guangdong landraces was significantly higher than those of the landraces from the other three regions. These results supported the hypothesis that China was a secondary center of sweetpotato diversity. The present results also supported the view that sweetpotato was first introduced to Guangdong and from there spread to other regions of China. The dendrogram based on the combined RAPD, ISSR and AFLP dataset could separate the 48 landraces into two groups: One mainly including 8 landraces from Guangdong and the other consisting of the remaining landraces from Guangdong and landraces from the other three regions. Thus, the utilization of Guangdong landraces should be specially considered in sweetpotato breeding.     

利用SRAP技术获得与抗甘薯茎线虫病基因相关的分子标记

用高感甘薯茎线虫病的甘薯品种徐薯18和高抗茎线虫病的徐78-1杂交,得到其F1分离群体。根据连续3年的抗病鉴定结果,从中挑选出8个高抗和8个高感茎线虫病的株系,构建抗病池和感病池。分别以抗感池基因组DNA为模板,用225对SRAP引物组合进行PCR扩增,其中77对引物组合在抗、感池间表现出多态性。通过一组小群体的进一步筛选,有4对引物组合被认为与甘薯茎线虫病抗性基因相关。这4对引物组合分别对2个亲本、抗感池和F1分离群体中的65个抗病株系和79个感病株系基因组DNA进行SRAP分析,有2对引物组合（a5b12和a9b11）各获得1个与甘薯茎线虫病抗性基因紧密连锁的分子标记SP1和SP2,它们与抗甘薯茎线虫病基因的遗传距离分别为4．86cM和4．17cM。获得的分子标记对克隆抗病基因和利用分子标记辅助选择提高育种效率具有重要的意义。     

吉林省脱毒甘薯品种引进与评价

对11个甘薯品种在吉林省进行了比较试验,商薯19、徐25-2产量明显高于其他品种;食5、徐薯23、徐55-2和紫0602品种自身特点鲜明,食味较好。以上品种在吉林省有推广市场。     

将水稻半胱氨酸蛋白酶抑制剂(Oryzacystatin I)基因导入甘薯品种

本研究采用根癌农杆菌介导法以12个甘薯品种作为受体材料,将OCI（Oryzacystatin I)基因导入甘薯品种中,获取7个品种的抗Kan再生植株,对获得的具有Kan抗性的再生植株进行PCR分子检测,初步结果证明已将外源OCI基因导入到4个甘薯品种(6个株系)的基因组中。     

应用Microsoft Visual FoxPro建立甘薯品种资源电子查询数据库

利用Visual Foxpro 6．0数据库管理和应用软件开发系统，对福建省农业科学院作物研究所保存的甘薯品种资源建立管理系统，实现对甘薯种质资源的保存、信息检索查询和应用，为甘薯育种工作者提供参考。     

中国甘薯地方品种的遗传多样性分析

 用RAPD、ISSR及AFLP分子标记，对来自中国安徽、福建、河南和广东4省的48个甘薯地方品种进行遗传多样性分析。用30个RAPD引物、14个ISSR引物和9对AFLP引物分别扩增出227条、249条和260条多态性带。从多态性带的数量和实验稳定性看，AFLP标记优于RAPD和ISSR标记。3种分子标记得出的结果，均揭示中国甘薯地方品种的遗传变异十分丰富，支持中国是甘薯的次生多样性中心的观点。品种遗传变异的地区间差异比较表明，广东地区的地方品种遗传变异高于其余3省，并且达极显著差异水平，从分子水平揭示广东应是中国甘薯的最早引入地，并向周边省及内陆地区扩散。研究发现，由3种标记产生的聚类图存在一些差异，但将3种标记产生的多态性带结合产生的聚类图可以很好地揭示48个地方品种的亲缘关系，所有品种聚为两大类，一类以8个广东地方品种为主，另一类由剩余的8个广东地方品种和其余3省的32个地方品种组成。因此，在进行甘薯育种时应重点考虑广东地方品种的利用。