新疆北部豆科饲用植物的寄生真菌及真菌病害的初步研究

本文报导了作者于1991年4月－10月间在新疆北部的阿尔泰地区、天山西部、准噶尔盆地西部及盆地以南等地调查采集的豆科饲用植物寄生真菌约70种，其中12个种为我国的新记录种，以及1个新种和1个新变种。它们不同程度地分别寄生、危害16个属约43种豆科饲用植物。引起白粉病、锈病、霜霉病、各种叶斑病、茎枯、根腐等87种病害。     

Role of host specificity in the speciation of <Emphasis Type="Italic">Ascochyta</Emphasis> pathogens of cool season food legumes

Ascochyta/legume interactions are attractive systems for addressing evolutionary questions about the role of host specificity in fungal speciation because many wild and cultivated cool season food legumes are infected by Ascochyta spp. and most of these fungi have described teleomorphs (Didymella spp.) that can be induced in the laboratory. Recent multilocus phylogenetic analyses of a worldwide sample of Ascochyta fungi causing ascochyta blights of chickpea (Cicer arietinum), faba bean (Vicia faba), lentil (Lens culinaris), and pea (Pisum sativum) have revealed that fungi causing disease on each host formed a monophyletic group. Host inoculations of these fungi demonstrated that they were host-specific, causing disease only on the host species from which they were isolated. In contrast to the strict association between monophyletic group and host observed for pathogens of cultivated legumes, Ascochyta fungi causing disease on wild bigflower vetch (Vicia grandiflora) were polyphyletic. Genetic crosses between several pairs of closely related, host-specific, and phylogenetically distinct Ascochyta fungi were fully sexually compatible. Progeny from these crosses had normal cultural morphology and segregation of molecular markers indicating a lack of intrinsic, post-zygotic mating barriers between the parental taxa. However, when progeny from a cross between a faba bean-adapted isolate (A. fabae) and a pea-adapted isolate (A. pisi) were assessed for their pathogenicity to the parental hosts, almost all progeny were non-pathogenic to either faba bean or pea. These results suggest that although these fungi have retained the ability to mate and produce progeny with normal saprophytic fitness, progeny are severely compromised in parasitic fitness. The host specificity of these fungi, coupled with the inability of hybrid progeny to colonize and reproduce on a host, may constitute strong extrinsic, pre-zygotic and post-zygotic mating barriers in these fungi and promote the genetic isolation and speciation of host-specific taxa. A phylogeny of the host plants is also being developed, and with more extensive sampling of pathogens and hosts from sympatric populations in the centre of origin, the hypothesis of cospeciation of pathogens and hosts will be tested. The objectives of this review are: (1) to summarize recent phylogenetic, host specificity and speciation studies of Ascochyta fungi, and (2) to suggest how current and future research using these pathosystems may lead to a better understanding of the role of host specificity in the speciation of plant-pathogenic fungi and the cospeciation of pathogens and their hosts.     

The sympatric Ascochyta pathosystems of Near Eastern legumes,a key for better understanding of pathogen biology

The primary and secondary centres of origin of domesticated plants are often also the places of origin of their pathogens. Therefore, the Near Eastern cradle of agriculture, where crop plants, their wild progenitors, and other con-generic taxa grow sympatrically, may hold some clues on the biology of the pathogens of the respective crops. Unlike the situation in the well-studied Near Eastern cereals and their important diseases, hardly any data are available on basic questions regarding grain legumes. What is the role of genetic diversity at resistance loci of the wild hosts and is it greater compared with the cultigens? Are populations of Ascochyta pathogens infecting wild legumes genetically distinct from populations infecting their domesticated counterparts, and if so, is this differentiation related to differences in host specialization or to adaptation to different ecological conditions? Do isolates originating from wild taxa exhibit a similar level of aggressiveness and have different aggressiveness alleles compared with those originating from domesticated grain legumes? In this review we propose an experimental framework aimed at gaining answers to some of the above questions. The proposed approach includes comparative epidemiology of wild vs. domesticated plant communities, co-evolutionary study of pathogens and their hosts, phenotypic and genetic characterization of fungal isolates from wild and domesticated origins, and genetic analyses of pathogenicity and parasitic fitness among progeny derived from crosses between isolates from wild and domesticated hosts.     

Grazing preference of Merino sheep for naturalized annual clover species relative to commonly sown clover species

Selective grazing of white clover (Trifolium repens) over grass species in temperate pastures results in reduced clover abundance and availability over time. Within sheep‐ and cattle‐grazed dryland (<800 mm annual rainfall) hill and high country areas of New Zealand, naturalized unsown annual clover species show greater persistence and abundance over sown clovers. With a view to understanding legume abundance in these areas, Merino sheep grazing preference was investigated for pure swards of naturalized species Trifolium dubium, T. glomeratum, T. arvense and T. striatum and commonly sown species T. repens and T. subterraneum. The Chesson–Manly preference index was used to explore the hypothesis that grazing preference differs between these species and changes as plants mature. Herbage offtake was quantified at vegetative (mid–late spring; November) and reproductive (early summer; December) stages of plant maturity. Significant preference distinctions between species (P < 0·05) occurred in December, with relative preference ranging from 0·248 for T. repens to 0·065 for T. dubium. Reduced relative preference for naturalized species was related to decreasing nutritive value from spring to summer, reflecting increased stem and flower sward content. Relative preference was negatively related to increasing acid detergent fibre and neutral detergent fibre and positively related to greater crude protein and dry‐matter digestibility. Naturalized annual clover species of lower grazing preference at reproductive maturity will benefit pasture sustainability via herbage and seed production and associated nitrogen‐fixation inputs.     

Effects of tropical legume silages on intake,digestibility and performance in large and small ruminants: A review

A meta‐analysis was performed to determine the effects of feeding ruminants with tropical legume silages on intake, digestibility and performance using a data set with 218 treatments (162 containing legumes, 56 without legumes) from 62 trials. First, a regression analysis was performed for diets containing legumes. Dry‐matter intake (DMI) and digestibility decreased with increasing legume proportion, with greater effects on large compared with small ruminants. Milk yield (MY) by dairy cows was not affected by legumes. Average daily gain (ADG) by cattle was maximized with legume silage inclusion between 200 and 400 g/kg DM, but no effect appeared for small ruminants. A second analysis compared diets without legumes with diets with medium (101–400 g/kg DM) and high (401–800 g/kg DM) legume inclusion. There were no differences in DMI, MY and ADG between the medium inclusion and without legumes, but all these parameters decreased with high inclusion. Digestibility was lower in diets with legume silages than in diets without legumes, regardless of the inclusion level. Feed conversion efficiency (FCE) was highest in diets with medium inclusion and lowest with high legume inclusion. While high legume inclusion negatively affected performance, including legume silages up to 400 g/kg DM seems to enhance or at least maintain MY, ADG and FCE, despite lower intake and digestibility. The reasons for such apparent paradox remain unclear. Well‐designed studies focusing on, e.g. microbial protein synthesis, energy metabolism, protein/carbohydrates characteristics, are required to better understand the effects of tropical legumes silages on nutrients’ utilization.     

Bio‐agronomic characterization and implications on the potential use as forage of Bituminaria bituminosa and B. morisiana accessions

Perennial forage legumes may be pivotal for improving the sustainability of Mediterranean rainfed farming systems. This study summarizes the outcomes of a study aimed at characterizing morphological and agronomic traits of new germplasm of Bituminaria bituminosa and B. morisiana in Mediterranean environments. Five B. morisiana and three B. bituminosa native populations were evaluated in a small‐plot field experiment in Sardinia (Italy) and compared with seven Spanish accessions of B. bituminosa. The two Bituminaria species differed greatly in morphological traits and the beginning of the flowering stage, and remarkable variations between species were found for forage production and its seasonal distribution, seed yield and persistence. Average cumulative dry‐matter yield was higher in B. bituminosa than in B. morisiana (+7.6%; 297 vs. 276 g per plant). Average 3‐year seed production varied greatly between accessions (from 0.3 to 141 g per plant). Differences for these traits were also found between Sardinian and Spanish germplasm of B. bituminosa. Four clusters were generated by K‐means clustering. Accessions included in cluster III exhibited a positive combination of favourable forage production, high seed yield and satisfactory persistence. Nonetheless, the cluster analysis did not highlight a sharp discrimination between Bituminaria species. The overall results revealed the potential role of Sardinian accessions of B. bituminosa and B. morisiana in extending the forage season and for increased resilience of grasslands in Sardinia and other Mediterranean regions under rainfed conditions.     

柱花草生产、加工与开发利用技术研究

柱花草多次收割比年终一次性收割干草产量较低,但猪的可消化粗蛋白产量反而提高。对柱花草捣碎后喂猪,在日粮中比例不超过6%时,与使用常规饲料的对照组比较,喂中猪时,日增重差异不显著,料肉比上升;喂大猪时,日增重上升,差异显著,料肉比下降。对劣质柱花草粉进行筛分,去除一部分粗纤维后喂鸡和猪,用量加大时料肉比显著上升,如同时加入复合酶制剂,则差异不显著。对柱花草进行脱叶,叶磨碎、叶维管束分离的干分离工艺,可以得到粗纤维较少和较多的两个组分,两者干重比例大致为叶的44%和56%左右。粗纤维较少的精叶粉比全株柱花草粉的鸡的氨真代谢率提高1.09倍,统计差异显著。     

桉树间作豆科牧草适应性筛选试验

研究13种豆科牧草与桉树(Eucalyptus spp.)间作的适应性筛选.结果表明:产草量以GC1581柱花草(Stylosanthes guianensis (Aubl.) Sw. cv. GC1581)最高(376.73 kg/hm²),与其他参试品种间差异极显著(P<0.01);大翼豆(Macroptilium atropurpureum (DC.) Urb.)、有钩柱花草(Stylosanthes hamata (L.) Taub. cv. Verano)和热研12号平托落花生(Arachis pintoi Krapov.et W.C. Greg.)不适合在桉树林间种植;参试品种的抗旱等级相差不大,其中以GC1581柱花草(Stylosanthes guianensis (Aubl.) Sw. cv. GC1581)最耐旱,抗旱等级为1.16;在6龄桉树林间种植豆科牧草,抗病性和抗虫性表现较好.     

食用豆种质资源表型数据分析系统的设计与构建

【目的】构建食用豆种质资源表型数据分析系统,为食用豆品种改良和基础研究提供丰富的种植资源和研究信息。【方法】借助河北省农林科学院粮油作物研究所保存的食用豆种质资源表型信息,基于B/S模式开发,利用LAMP（Linux+Apache+MySQL+Perl/Python）环境,设计并构建了在线食用豆种质资源表型数据分析系统（https://breeding.biobin.com.cn/germ）,并展示了该系统的主要功能和使用方法。【结果】构建了由数据层、处理层、表现层构成,可进行表型数据导入、检索与编辑的食用豆种质资源表型数据分析系统,该系统结合相关工具可进行表型相关性、层级聚类、划分聚类、遗传多样性指标等分析,且分析结果可视化。其中,表型鉴定可进行表型相似性与性状相关性分析,分析结果以雷达图或者线性回归图形式展示;表型相似性分析可以快速比较多个材料之间的数据,综合评价多个性状,选择更符合预期的育种材料;性状相关性分析可以分析任意两个性状之间的关联性,得到性状之间的关联程度。【结论】食用豆种质资源表型数据分析系统的构建有效解决了种质资源表型数据信息保存分散、不标准、分析利用困难等问题,实现了资源数字化管理、分析和共享,可用于我国食用豆育种及相关性状分析研究。