Genetics of resistance to ascochyta blight in chickpea (Cicer arietinum L.)

Summary Six chickpea lines resistant to Ascochyta rabiei (Pass.) Lab. were crossed to four susceptible cultivars. The hybrids were resistant in all the crosses except the crosses where resistant line BRG 8 was involved. Segregation pattern for diseases reaction in F₂, BCP₁, BCP₂ and F₃ generations in field and glasshouse conditions revealed that resistance to Ascochyta blight is under the control of a single dominant gene in EC 26446, PG 82-1, P 919, P 1252-1 and NEC 2451 while a recessive gene is responsible in BRG 8. Allelic tests indicated the presence of three independently segregating genes for resistance; one dominant gene in P 1215-1 and one in EC 26446 and PG 82-1, and a recessive one in BRG 8.Research paper No. 3600     

基于网络的鸡病防治与诊断专家系统的设计

目前中国鸡病防治中存在一些暂时无法解决的难题,如基层中鸡病诊断专家缺乏、鸡病防控不及时等。基于现状,利用计算机网络技术和人工智能技术,将SQL数据库和ASP.NET技术相结合,设计并开发了基于网络的鸡病防治与诊断专家系统。该系统将鸡病诊断和鸡病防治知识进行集成,采用基于规则的模糊化的混合推理策略,实现了鸡病诊断和防治的数字化和智能化,用户可通过网络实现鸡病诊断、鸡病防治、鸡群管理、知识查询和统计分析等功能。经验证性试验和专家评测,该系统结构合理,功能完善,可以满足广大基层用户的需求,具有一定的推广应用前景。     

甜瓜新品系的选育及可用性评价

利用网纹甜瓜和哈密瓜类型材料杂交，经6－7代系谱选择，选育出了3个网纹甜瓜新品系，并对其稳定性、抗病性和配合力进行了综合评价。结果表明：品系1、品系2表现出高度的一致性和遗传稳定性；品系1对白粉病呈HR抗性，品系2呈R抗性，品系3呈MR抗性；品系1和品系3单果重的一般配 力效应呈正向效应（GCA值分别为0．02和0．09），品系2的网纹一般配合力高（GCA值为0．16），品系3的单果重、果肉厚、糖含量均呈正向效应。     

患出血病鲫鱼主要组织可溶性蛋白质变化的研究

采用SDS-聚丙烯酰胺凝胶电泳法(SDS-PAGE)对正常和患出血病的鲫鱼心、肝、肾、鳃、脑、肌肉、肠、眼8种组织中可溶性蛋白质进行比较分析。结果表明：病鱼的心、肝、肾、鳃、脑、肌肉6种组织的蛋白质电泳谱带与正常鱼相比有较大变化，心和肾各缺失5条谱带；肝新诱导出1条谱带，另有1条谱带缺失；鳃中新诱导出2条谱带，有2条谱带缺失；脑中增加了4条新谱带，1条谱带缺失；肌肉新增5条谱带。说明鱼在遭受病原菌侵袭后，蛋白质的合成代谢受到较大影响。这些变化可作为辅助疾病诊断的生化指标。     

抗病优质大白菜“秋白70”的选育

优质、抗病的大白菜新品种——秋白70是利用天津青麻叶为母体，进行游离小孢子培养，并结合人工接种鉴定技术于2002年育成功。该品种长势旺，成熟期70d，株型较直立，株高48cm，开展度51cm，外叶8片，叶形长倒卵形，叶色深绿，叶面多皱，绿帮；叶球长筒形，颜色绿，叶球内叶颜色浅黄，心叶拧抱，舒心；叶球高44cm，直径14cm，单球重2.2kg左右，净菜率82.3%。品质优良，口味佳。较抗霜霉病和病毒病。平均产量10.8kg/m2。     

FMDV OA/58病毒株VP1蛋白结构构建与B细胞抗原表位的预测

以口蹄疫病毒株OA/58 RNA为模板,反转录并扩增目的cDNA,然后与pGEM-T easy载体连接并转化JM109菌株,提取的重组质粒用凝胶电泳、PCR和EcoR Ⅰ酶切法鉴定.运用同源模建得到OA/58 VP1蛋白3D结构,并结合理化性质、亲水性、可塑性和免疫原性进行分析,预测OA/58 VP1的抗原表位.结果 OA/58 VP1存在多个潜在的抗原表位位点,可能的蛋白质抗原表位区域:2～11,15～35,38～50,77～88,90～107,121～125,131～135,140～149,154～163,169～175,178～189,197～213.应用同源模建得到的OA/58 VP1蛋白3D模型来预测其B细胞表位,为进一步研究OA/58 VP1功能,构建突变体和选择表达新型OA/58 VP1蛋白分子提供有参考价值的信息.     

Evaluation of common wheat cultivars for tan spot resistance and chromosomal location of a resistance gene in the cultivar 'Salamouni'

A total of 50 wheat (Triticum aestivum L.) cultivars were evaluated for resistance to tan spot, using Pyrenophora tritici‐repentis race 1 and race 5 isolates. The cultivars ‘Salamouni’, ‘Red Chief’, ‘Dashen’, ‘Empire’ and ‘Armada’ were resistant to isolate ASC1a (race 1), whereas 76% of the cultivars were susceptible. Chi‐squared analysis of the F₂ segregation data of hybrids between 20 monosomic lines of the wheat cultivar ‘Chinese Spring’ and the resistant cultivar ‘Salamouni’ revealed that tan spot resistance in ‘Salamouni’ was controlled by a single recessive gene located on chromosome 3A. This gene is designated tsn4. The resistant cultivars identified in this study are recommended for use in breeding programmes to improve tan spot resistance in common wheat.     

Identification of novel QTL for resistance to crown rot in the doubled haploid wheat population 'W21MMT70' × 'Mendos'

Crown rot (causal agent Fusarium pseudograminearum) is a fungal disease of major significance to wheat cultivation in Australia. A doubled haploid wheat population was produced from a cross between line ‘W21MMT70’, which displays partial seedling and adult plant (field) resistance to crown rot, and ‘Mendos’, which is moderately susceptible in seedling tests but partially resistant in field trials. Bulked segregant analysis (BSA) based on seedling trial data did not reveal markers for crown rot resistance. A framework map was produced consisting of 128 microsatellite markers, four phenotypic markers, and one sequence tagged site marker. To this map 331 previously screened AFLP markers were then added. Three quantitative trait loci (QTL) were identified with composite interval mapping across all of the three seedling trials conducted. These QTL are located on chromosomes 2B, 2D and 5D. The 2D and 5D QTL are inherited from the line ‘W21MMT70’, whereas the 2B QTL is inherited from ‘Mendos’. These loci are different from those associated with crown rot resistance in other wheat populations that have been examined, and may represent an opportunity for pyramiding QTL to provide more durable resistance to crown rot.     

Linkage of downy mildew resistance genes Pd 1 and Pd 2from Allium roylei Stearn in progeny of its interspecific hybrid with onion (A. cepa L.)

Summary Male meiosis of the interspecific hybrid between Allium roylei and A. cepa is undisturbed relative to its parents. Based on meiotic data, A. roylei is concluded to be a closer relative of A. cepa than A. fistulosum. Segregation ratios for downy mildew resistance among BC₁ and F₂ progenies from the F₁ between A. roylei and A. cepa indicate the presence of two dominantly inherited, weakly linked nuclear resistance genes, Pd ₁ and Pd ₂, in A. roylei (recombination frequency 0.32±0.03). Presumably Pd ₁ and Pd ₂are the first genes described in Allium residing in one linkage group. The prospects of exploiting A. roylei in onion breeding seem very promising.     

Location-Specific and Across-Location Selections for Seed Yield in Populations of Common Bean, Phaseolus vulgaris L.

Two populations of common bean, Phaseolus vulgaris L., were used to make three independent location-specific selections at Palmira, Quilichao, and Popayán, Colombia. Also, three across-location selections were made by alternating generations between Palmira and Popayan, between Quilichao and Popayán, and among Palmira, Quilichao, and Popayán. The seven highest yielding lines selected from each environment and population along with 14 parents and two checks were evaluated for seed yield, seed weight, maturity, and reaction to an-thracnose, angular leaf spot, and common bacterial blight. Mean squares due to evaluation and selection environments, selected lines, and their interactions were significant for all traits. Mean yields of selected lines were higher than the mean of parents in both populations. Among location-specific selections, lines yielded higher at their respective selection site. Moreover, selections made at Popayán were higher yielding than those made at Quilichao or Palmira when tested across locations and years. Use of Popayán, a relatively wetter and cooler site, either alone or in combination with other locations resulted in higher yield, higher seed weight, and higher resistance to anthracnose. On the average, location-specific selections were lower yielding than the across-location selections. Among across-location selections, those selected between Palmira and Popayán were the highest yielding in both populations. Selections at Palmira and across all three locations resulted in greater stability.