Validation of molecular markers for pathogen resistance in potato

DNA markers have a large potential to improve efficiency and precision of conventional plant breeding programmes based on marker‐assisted selection (MAS). In our study, we have evaluated the predictive abilities of the SCAR marker RYSC3 and the CAPS marker GP122₅₆₄ with regard to the PVY resistance genes Ry_adg and Ry_sto, respectively, and of marker TG689 linked to H1 conferring resistance to Globodera rostochiensis and marker HC associated with high levels of G. pallida resistance. The evaluations were made in 28 cultivars and accessions and in 219 progeny genotypes descending from ten different crosses. We observed in all evaluated cultivars and accessions the expected marker patterns according to their phenotypic classification into resistant and susceptible genotypes. However, in part considerable discrepancies were observed when analysing progeny of controlled crosses involving these resistance sources, particularly with respect to H1. Based on these results, practical aspects for the efficient implementation of marker‐assisted selection are discussed, which consider the genetic origin of the material, costs aspects and methodology applied.     

桃肉色、果皮茸毛性状的SSR标记筛选

[目的]研究与桃果肉颜色和果皮茸毛性状相关的SSR标记,为桃早期分子标记辅助育种提供参考依据.[方法]以油蟠桃98-5-8与普通桃91-42-51杂交的F1分离群体74个单株为材料,对其果实白肉/黄肉、有毛/无毛两个性状进行SSR分子标记.[结果]在66对引物中,引物UDP96-005和pchgms3、UDP97-401和CPSCT030分别在白肉/黄肉单株、有毛/无毛单株及混合基因池间扩增出差异条带.表型性状与标记连锁结果表明,SSR标记UDP96-005（164 bp）与白肉性状连锁,遗传距离为4.06 cM; SSR标记CPSCT030（191 bp）与有毛性状连锁,遗传距离为8.2 cM.对20个桃栽培品种进行验证,UDP96-005标记对白、黄肉品种的检测符合率为85％,CPSCT030标记对有无茸毛品种的检测符合率为50％.[结论]筛选获得分别与桃白肉、有毛性状连锁的SSR标记UDP96-005与CPSCT030,可用于桃分子标记辅助育种,并为发掘与桃果肉颜色和茸毛性状相关基因奠定基础.     

Development and validation of a PCR-based functional marker system for the brown planthopper resistance gene Bph14 in rice

Brown planthopper (BPH) is the most damaging rice pest globally. Resistant varieties are the most effective and environmental strategy for protecting the rice crop from BPH. Functional markers (FMs) designed from polymorphic sites within gene sequences affecting phenotypic variation are highly efficient when used for marker assisted selection (MAS). Bph14 is the first and only cloned insect resistance gene so far in rice. Compared to the sequences of its non-effective alleles there are a number SNP differences. In this study, the method of allele-specific amplification (ASA) was adopted to design a simple, co-dominant, functional marker Bph14P/N for Bph14. Bph14P/N was combined with two specific dominant markers: one, named Bph14P, targets the promoter region of Bph14 and amplifies 566 bp fragments; and the other, Bph14N, targets the LRR region of bph14 and amplifies 345 bp fragments. Specificity and applicability of the functional marker system were verified in two breeding populations and a Chinese mini core collection of Oryza sativa. We recommend the use of this simple, low-cost marker system in routine genotyping for Bph14 in breeding populations.     

分子标记在动物抗病育种中的研究进展

综述了利用分子标记寻找抗性 /易感性基因、与抗性 /易感性相关候选基因和定位抗性 /易感性 QTL以及特定分子标记与它们的紧密连锁关系的国内外研究动态 ,从而进行标记辅助选择 ( MAS)抗病育种。     

Identifying the markers and tagging a leucine-rich repeat receptor-like kinase gene for resistance to anthracnose disease in vegetable cowpea [Vigna unguiculata (L.) Walp.]

Anthracnose caused by the fungus Colletotrichum lindemuthianum is the most destructive disease of cowpea. Field-type cowpeas show various levels of resistance, whereas pole-type vegetable cowpeas are highly susceptible. Transfer of resistance available in field types to vegetable types is a major breeding objective in cowpea. This paper details the development of an F₂ mapping population by crossing field-type cowpea variety Kanakamony (Vigna unguiculata ssp. cylindrica) with pole-type vegetable cowpea variety Sharika (Vigna unguiculata ssp. sesquipedalis), screening this population with artificial inoculation and Bulked Segregant Analysis (BSA) with random marker systems Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeats (ISSR); the objective is to identify the markers linked with major resistance-contributing genes. RAPD primer OPA02 has yielded marker at 850 bp in susceptible genome, whereas ISSR primers UBC810 and UBC811 have yielded markers at 1.4 kb and 1.5 kb respectively in resistant genomes. These markers were reproducible and their linkage with resistance and suitability in marker assisted selection (MAS) were confirmed through co-segregation analysis in F₃ population. UBC811 marker was eluted, cloned on pGEM-T, and sequenced. The sequence had shown that this marker is anchored on LRR receptor-like serine/t\hreonine protein kinase gene which could be involved in the resistance mechanism.     

畜禽抗病育种研究进展

随着分子生物学技术的发展,抗病育种的重要性越来越显现出来。本文简要介绍了抗病育种的必要性、抗病育种的遗传基础、抗病育种的方法,最后对抗病育种将来的发展进行了展望。     

烟草染色体片段代换系的构建与遗传评价

以综合性状优良的烤烟种质Y3为轮回亲本,抗烟草黑胫病(0、1号生理小种)和赤星病的雪茄烟种质Beinhart1000-1及优质烤烟品种K326为供体亲本,连续回交并结合分子标记辅助选择,构建国内外第一套由256个具有烤烟Y3遗传背景并渐渗有Beinhart1000-1和K326染色体片段株系代换系群体。该群体携带377个代换片段,分布于烟草24条连锁群上。每个株系携带1~5个代换片段,代换片段长度介于0.05~36.88 cM,平均长度7.75 cM。代换片段重叠累加总长度为2922.57 cM,是烟草基因组总长度的2.61倍。代换片段覆盖总长度为1114.32 cM,烟草基因组覆盖率为99.45%。本研究构建的片段代换系可用于烟草基因定位、复杂性状的QTL分析和标记辅助选择育种。     

与粳稻BT型细胞质育性恢复基因连锁的实用SSR标记的筛选

以粳稻BT型细胞质育性恢复基因Rf-1位点的近等基因系、77个测交父本以及5个不育系与77个测交父本配制的178个测交组合F1为材料,利用义献报道的与Rf-1连锁的12对SSR标记引物,筛选近等基因系间与育性等位基因连锁带型一致的SSR标记,再用后者扩增测交父本,并调查测交F1植株的自然结实率,验证父本带型与育性恢复力的关系.结果表明:住12对SSR标记引物中,RM5629在六千辛A和六千辛B中均扩增出120 bp的片段,在恢复基因供体77302-1和8个近等基因系六千辛R株系中均扩增出110 bp的片段,在六千辛A/六千辛R的杂种F1中扩增出110 hp和120 bp的互补片段.6427 R系列、武育粳3号R系列、六盐189R系列、157TR系列、4016LHR系列、4016R和秀水04R同质恢复系以及8个常用的非同质恢复系的RM5629标记基因型与育性恢复力的符合率均为100%,3726R系列同质恢复系的标记基因型与育性恢复力的符合率为94.1%,平均为97.3% RM5629可作为Rf-1分子标记辅助选抒的实用SSR标记.     

水稻耐盐相关QTL研究进展

盐害是影响水稻生长的非生物胁迫之一。综述了近年来水稻耐盐性数量性状基因座位（QTL）定位和基因克隆所取得的进展,并提出了建议,为今后深入开展水稻耐盐性研究提供了参考。