强健性多丝量蚕品种871、872的育成

采用杂交育种结合系谱选择方法育成了强健性多丝量品种871、872,通过1993～1994两年攻关点联合鉴定及全国桑蚕品种鉴定,结果表明;万蚕收茧量、万蚕茧层量、万蚕产丝量分别比对照种提高11％～15％、11％～18％、15％,茧丝长1200～1400m,出丝率17．42％～20．68％,净度94～96分,是一对体质较强,丝质优良兼耐氟化物污染,繁育性能较好的优质春、秋兼用多丝量蚕品种。     

Variation in virulence and resistance in the bean-bean rust pathosystem in Ecuador

Twenty two Uromyces appendiculatus isolates were tested on 20 differential and 25 Ecuadorian Phaseolus vulgaris cultivars in the seedling stage. Based on the infection types 20 races could be discerned. The Ecuadorian cultivars differed greatly in their reaction to the isolates, from resistant to only one isolate (`Red Small Garden') to resistant to all isolates (’G2333‘). The isolates showed a wide range of virulence to the Ecuadorian cultivars, from virulent to only two cultivars (isolate 13) to virulent to 21 cultivars (isolates 5 and 23). Seven cultivars with a basically susceptible infection type appeared to differ greatly in quantitative resistance when tested in three consecutive crop cycles. The disease severities in percentage leaf area affected averaged over the three cycles ranged between 83.9% for ‘Red Small Garden’ and 13.1% for ‘INIAP-414’. Race-specific resistance does not seem an advisable breeding strategy, but the quantitative resistance offers a good alternative.     

陕西关中地区节节麦上小麦条锈菌群体结构与毒性特征

为掌握节节麦上小麦条锈菌的群体结构,对采自陕西关中8个点40个小麦田间的节节麦锈病标样进行了分离鉴定.结果 表明:从分离到的40个小麦条锈菌菌株在19个中国鉴别寄主上共鉴定出6种生理小种共30个,包括CYR34(25％)、CYR33 (5％)、CYR32 (35％)、Hy-30 (5％)、Hy-101 (2.5％)和S...     

桑青枯病描述及研究中的几个问题探讨

针对桑青枯病(mulberry bacterial with)的一些错误描述及研究中的误区,阐述了国内外桑青枯病发生情况、正确的学名及小种与生化类型。研究提出了桑青枯病致病性测定新方法——离体桑枝注射接种法;首次明确了桑青枯菌中除生化型5(小种5)外还存在较多的4型菌(小种1)。控制该病的危害需着重抗病育种和生物防治。     

用可溶性蛋白电泳法鉴定玉米小斑病菌生理小种

分别从玉米小斑病菌T、C、O三个生理小种的菌丝中提取可溶性蛋白,进行聚丙烯酰胺凝胶电泳(PAGE)和SDS聚丙烯酰胺凝胶电泳(SDS-PAGE),经多次比较试验,T、C、O小种的蛋白质图谱主带基本相同,个别带存在一定差异,而同一生理小种不同菌株间差异甚小.建议运用病原菌蛋白电泳的方法,作为小种分类、病害预测的手段之一.     

影响大豆胞囊线虫生理小种鉴定因素探讨

大豆胞囊线虫(soybean cyst nematode,SCN)引起的病害能给大豆生产造成严重损失。探索影响大豆胞囊线虫(soybean cyst nematode,SCN)生理小种鉴定的因素对指导抗线育种工作具有重要意义。本研究以Lee68为材料,接种一定浓度的SCN4虫卵,在不同温度梯度的培养箱中培养,研究温度对大豆胞囊线虫生长的影响;以Riggs鉴定模式中的5个寄主为材料,接种一定浓度梯度的SCN2虫卵,研究接种浓度对鉴定结果的影响;从土壤相对含水量方面研究水分对大豆根系发育的影响。研究结果表明:在设定的温度梯度中,培养温度25℃/22℃(光/暗),Lee68上生长的胞囊数目最多,与其它几个温度培养条件相比,单株胞囊平均数达到差异显著水平,是胞囊生长最适宜温度;接种虫卵为1 200~24 000个/杯时,鉴定结果是正确的,超出这个接种范围,鉴定结果不稳定;一天浇水两次,浇水前/后土壤含水量为4%~7%/15%~18%,最有利于根系发育。本研究结果可为大豆胞囊线虫生理小种鉴定和抗线育种工作提供参考。     

The Athletic Performance of Thoroughbred Racehorses out of Mares with Suspected Placentitis during Gestation

Thoroughbred mares treated for signs of placentitis are potentially costly to farms and owners. Although these treatments often are effective, the resulting foal may require expensive aftercare. The current study investigated the future racing performance of foals from mares treated for clinical and subclinical signs of placentitis compared with matched control mares that had no signs of placentitis producing foals on the same farms. In total, 190 horses born from mares with suspected placentitis met the criteria for analysis and were matched with 190 horses born on the same farm. Mare data and percentage of stakes winners in each group were analyzed with Student t test. Analysis between pairs of horses was done using a paired t test for number of starts, wins, places, shows, and amount earned. Significance was set at a P value of <.05. Mares with suspected placentitis were slightly older than control mares, had slightly shorter lengths of gestation, and had a longer interval to subsequent pregnancy than control mares (P < .05). Horses out of suspected placentitis mares that were racing as 2 year olds in the study had no difference in starts, wins, places, shows, and percentages of black-type race winners; however, this group earned more than their matched control pairs (P < .05). Older horses (3 year olds) out of suspected placentitis mares had no differences in number of starts, wins, places, shows or amount earned; however, the matched control older horses had more black-type race winners (P < .05). The information from this study may aid owners when making decisions about treatment options.     

合肥郊区番茄青枯病病原细菌致病力测定

根据细菌的形态、染色反应、生长适湿、培养性状、生理生化反应和致病性等性状的测定,将引致合肥地区番茄青枯病的病原细菌鉴定为青枯假单胞菌。并按照致病性和生理生化反应,将其定为致病性性强的小种１或生物型Ⅲ。     

大豆抗大豆孢囊线虫的抗性分级标准研究

2002年,用塑料钵柱法对35份大豆主栽品种进行了抗大豆孢囊线虫(SCN)4号生理小种的抗性研究。采用IP分级方法,以晋豆23号的孢囊量作为IP分级标准的基数,对主栽品种划分抗SCN4号生理小种的抗性等级。结果表明,6份高抗多生理小种抗源的抗性稳定,2份黑种皮品种表现高抗,4份黄种皮亲本表现中抗,11份为感病品种,12份为高感品种。以适合当地的主栽品种的孢囊量作为IP分级标准的基数,有利于黄种皮中抗品种的利用,将拓宽抗病虫育种的范围,为筛选高抗SCN4号生理小种的黄种皮抗源提供新方向。