Odeny D A, Jayashree B, Gebhardt C, Crouch J
University of Bonn, Centre for Development Research (ZEFc), Walter-Flex Str,3 53113 Bonn, Germany.
BMC Res Notes. 2009 Mar 6;2:35. doi: 10.1186/1756-0500-2-35.
Pigeonpea is a nutritious tropical legume with several desirable characteristics but has been relatively neglected in terms of research. More efficient improvement can be achieved in this crop through molecular breeding but adequate molecular markers are lacking and no linkage map has been developed so far. Microsatellites remain the markers of choice due to their high polymorphism and their transferability from closely related genera. The overall objective of this study was to develop microsatellite markers from an enriched library of pigeonpea as well as testing the transferability of soybean microsatellites in pigeonpea.
Primers were designed for 113 pigeonpea genomic SSRs, 73 of which amplified interpretable bands. Thirty-five of the primers revealed polymorphism among 24 pigeonpea breeding lines. The number of alleles detected ranged from 2 to 6 with a total of 110 alleles and an average of 3.1 alleles per locus. GT/CA and GAA class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats respectively. Additionally, 220 soybean primers were tested in pigeonpea, 39 of which amplified interpretable bands.
Despite the observed morphological diversity, there is little genetic diversity within cultivated pigeonpea as revealed by the developed microsatellites. Although some of the tested soybean microsatellites may be transferable to pigeonpea, lack of useful polymorphism may hinder their full use. A robust set of markers will still have to be developed for pigeonpea genome if molecular breeding is to be achieved.
木豆是一种营养丰富的热带豆类，具有多种优良特性，但在研究方面相对被忽视。通过分子育种可以在这种作物上实现更有效的改良，但缺乏足够的分子标记，且目前尚未构建连锁图谱。由于微卫星具有高度多态性且可从近缘属转移，因此仍然是首选标记。本研究的总体目标是从木豆的富集文库中开发微卫星标记，并测试大豆微卫星在木豆中的可转移性。
为113个木豆基因组简单重复序列（SSRs）设计了引物，其中73个扩增出可解读的条带。35个引物在24个木豆育种系中显示出多态性。检测到的等位基因数量在2至6个之间，总共110个等位基因，每个位点平均3.1个等位基因。GT/CA和GAA类重复序列分别是最丰富的二核苷酸和三核苷酸重复序列。此外，在木豆中测试了220个大豆引物，其中39个扩增出可解读的条带。
尽管观察到形态多样性，但所开发的微卫星显示，栽培木豆内部的遗传多样性很少。虽然一些测试的大豆微卫星可能可转移到木豆中，但缺乏有用的多态性可能会阻碍它们的充分利用。如果要实现分子育种，仍需为木豆基因组开发一套强大的标记。
