提莫菲维小麦染色体的C-带分析

对提莫菲维小麦的根尖细胞染色体进行C-带分析,以明确提莫菲维小麦的染色体C-带带型特点。结果表明:提莫菲维小麦具有14对染色体,其染色体带型公式为:2 n=28=4 IT++4 IT++6 CIT++6 I+2 IT+2 CI+2 CIT+S+2 CIS,共包括98条带,其中长臂具有57条带纹,包括50条中间带(I),7条端带(T);短臂具有35条带纹,包括30条中间带(I),3条端带(T),2条随体带(S);另外还有着丝点带(C)6条。提莫菲维小麦G组染色体的异质化程度明显高于A组染色体,G组染色体的C-带带型与普通小麦B组染色体非常相似,因此G组染色体可能与B组染色体存在部分同源性。     

Further Studies on the Restoration of Fertility in Triticum durum×T. timopheevi Hybrids

Twenty one F₁ hybrids involving three Triticum durum cultivars and eleven forms of T. timopheevi were backcrossed to their respective durum parents. Backcross fertility (BC₁ grain set) of these sterile hybrids improved with the rise in temperature at the time of pollination. A mean temperature of less than 20 °C results in poor seed set while higher mean temperatures around 24 °C result in increased seed set. It is suggested that a large number of backcross seeds can be produced by pollinating these hybrids late in the season, i.e., after 20th of March in northern India.     

小麦“T”型胞质雄性不育杂种优势的表现及其遗传机理的研究

本试验用“Ｔ”型胞质不育系，对应保持系及恢复系为材料进行了两个问题的研究，即杂种优势的表现及杂各种优势的遗传机理。结果表明，在所研究的１１个性状上，平均优势普遍存在，超亲优势也较为明显，但超标优势较低。这种“超亲容易超标准”的现象是影响杂种小麦在生产上推广利用的重要因素之一。对杂种优势的遗传机理分析结果表明，在总遗传方差中，加性效应方差与非加性效应方差所占的比重因性状不同而有异，加性效应与非加性效     

T型细胞质对杂种小麦农艺性状的影响

用不育系与恢复系杂交得到的杂种aF_1同相应保持系与恢复系所得到的杂种bF_1差异所分析的细胞质效应结果表明,aF_1表现穗粒数明显减少,千粒重显著提高,其它性状没有明显差异。总的看来,T 型细胞质还是目前较为理想的不育胞质。     

提莫菲维小麦和偏凸山羊草不育细胞质对小麦旗叶光合功能的影响

 本文研究了提莫菲维小麦（Triticum timopheevi）和偏凸山羊草（Aegilops ventricosa）雄性不育细胞质对小麦旗叶光合功能的影响。研究结果表明，与普通小麦细胞质相比，提莫菲维小麦和偏凸山羊草细胞质会在不同程度上对小麦旗叶的光合速率、量子效率、气孔导度、叶肉导度、水分利用效率、光系统Ⅰ活性及Hill反应活性产生负效应，提莫菲维小麦细胞质的负效应小于偏凸山羊草。旗叶全展初期，普通小麦细胞质的RuBPCase初始活性和总活性显著高于提莫菲维小麦细胞质，提莫菲维小麦细胞质又显著高于偏凸山羊草细胞质；而在RuBPCase初始比活性及总比活性方面，普通小麦细胞质和提莫菲维小麦细胞质相近，这两者显著高于偏凸山羊草细胞质。异源细胞质雄性不育系育性恢复后，旗叶光合速率、RuBPCase初始活性和初始比活性等均有显著提高。     

亲本类型对提型恢复系自身育性及其恢复度的影响

通过对不同世代提型恢复系自身结实率的连续考察,发现经过 F_2代的严格选择后,多数 F_3恢复系的自身结实率超过了80%;但同一株系后代的不同个体之间有一定的差异。这种差异可以一直保持到 F_7代。F_5群体的自身结实率与其恢复度呈显著正相关,r=0.879。亲本类型只影响恢复基因在后代群体中的纯合速度,与高代恢复系(F_5代以上)的结实率和恢复度无明显相关。自身结实率高且群体中变异系数小的恢复系对所有的不育系都能高度恢复;而结实率高但变异系数大的恢复系其恢复度会因不育系的不同而变化。主效恢复基因未完全纯合可能是高代恢复系的恢复度在不同不育系上出现分离的主要原因。对根据自身结实率及其变异系数进行恢复系选育的效率进行了讨论。     

Genetic distance between Triticum timopheevi Zhuk., T. aramticum Jakubz. and T. aestivum L.

The genetic distances between two cultivated wheat (Triticum aestivum L.) varieties (Martonvásári 9, Martonvásári 15), a Martonvásári 9 line possessing the crossability gene krl, and 21 accessions of T. timopheevi Zhuk. and T. araraticum Jakubz. were estimated, based on agro-morphological, physiological and biochemical analysis of data. Cluster analysis based on Mahalanobis' D² values was applied. All 21 accessions of T. timopheevi and T. araraticum could be classified into eight clusters. Clusters I and II consisted of all the T. timopheevi, while T. araraticum was located in six clusters. Discriminant analysis was applied to test significant differences between cluster pairs. The genetic distance (GD) based on the electrophoretic data of gliadins indicated two types of electrophoregrams in T. timopheevvi, distinguished as groups A and B. T. araraticum accessions were variable as regards the spectra. Mean, minimum and maximum GD were estimated within and between different wheat groups based on acid polyacrylamide gel electrophoresis.     

Localization of Genes in Rye that Restore Male Fertility to Hexaploid Wheat with timopheevi Cytoplasm

Four sets of wheat-rye addition lines were screened to localize genes in rye that restore male fertility to hexaploid wheat with timopheevi cytoplasm. One gene, designated Rfc3, was physically located in the distal 40 % of the long arm of chromosome 6R. No allelic variation at Rfc3 was found; normal male fertility was consistently observed in all F₁ hybrid combinations tested. A second gene, designated Rfc4, was located on the long arm of chromosome 4R. Variation between chromosomes 4R in the level of restoration was observed; fertility in hybrids ranged from 0 % to about 50 % of normal. Attempts to genetically map Rfc4 were inconclusive but suggested it was located 16.1 cM from the telomere of the long arm and at least 8.0 cM from the centromere. These restorers, particularly Rfc3, may have potential in hybrid wheat breeding programs and can be manipulated for production of male sterile triticale lines.     

影响小麦提型不育系种子质量的遗传因素

根据Ｔ型不育系和恢复系,不育系和保持系的两套双列杂交试验以及川７Ａ和其它保持系的４套回交试验。对影响Ｔ型不育系种饱满度和发芽率的遗传因素进行了分析,发现不育系异交子粒的发育进程和充实程度主要取决于母体的基因型;而不育系种子的发芽率则受母体基因型和花粉供体基因型的共同影响。用川７Ｂ给其它不育系授粉得到的杂交种子,其发芽率明显地高于这些不育系与同型保持系杂交产生的种子;不育系种子的饱满度也因有了川７Ｂ     

提莫菲维小麦与葡萄牙野燕麦远缘杂交后代的SRAP分析

采用SRAP技术分析提莫菲维小麦与葡萄牙野燕麦远缘杂交后代的真实性及其特点。结果表明,22对SRAP引物中,20对引物在双亲间扩增出多态性条带,其多态性比率为73.81%。me4-em1、me3-em5、me4-em3和me3-em3四对引物在提莫菲维小麦与葡萄牙野燕麦杂交F3株系中扩增出双亲特异带,表明该F3株系具有双亲的遗传物质,该F3株系是提莫菲维小麦和葡萄牙野燕麦成功属间杂交的真实杂种后代。在F3株系的扩增结果中部分双亲带型消失,并且提莫菲维小麦消失的带数远少于野燕麦的;同时有非父母标记新带型出现。杂种后代DNA序列的这种变化可能有利于新形成异源多倍体小麦的快速进化、遗传协调和遗传稳定性。