小麦-华山新麦草7Ns异附加系的分子细胞遗传学研究

为了给有效利用华山新麦草基因提供新的种质材料,利用细胞遗传学、分子标记等技术,结合田间农艺性状考察,对从小麦-华山新麦草七倍体材料H8911-99与硬粒小麦D4286杂交F4代分离群体中选育的杂交后代12DH25进行了鉴定。华山新麦草基因组特异SCAR标记鉴定表明,12DH25含有华山新麦草遗传物质;有丝分裂和花粉母细胞减数分裂中期I染色体数为2n=44=22Ⅱ,基因组原位杂交(GISH)出现两条杂交信号,且能配对,表明两条外源染色体是华山新麦草的一对同源染色体。选取定位于小麦7个部分同源群上的28对STS标记对12DH25及其亲本基因组DNA进行扩增,定位于小麦第7同源群上的STS标记BE591127和BG274576能在12DH25中扩增出华山新麦草特征条带,将12DH25附加的华山新麦草染色体归属于小麦第7部分同源群。由此确定矮秆材料12DH25是一个稳定的小麦-华山新麦草7Ns二体异附加系。

Molecular and Cytogenetic Characterization of a Triticum psathyrostachys 7Ns Addition line

A wheat P. huashanica alien addition line 12DH25 was developed from the F₄ progeny of H8911 99 and Triticum durum cv. D4286. Analysis on morphology, cytology and SCAR markers were adopted to identify this alien addition line 12DH25. The results showed that 12DH25 presented favorable agronomic traits and its average plant height was 55.64 cm, which was very low. A SCAR marker was developed to distinguish the wheat lines carrying chromosomes derived from P. huashanica, with a specific band in the plant of 12DH25. The chromosome number of 12DH25 in root tip cells were 44 with 22 bivalents observed in most PMC at M I, and a pair of Ns chromosome with fluorescence signals appeared in genomic in situ hybridization (GISH) analysis using P. huashanica whole genomic DNA. STS markers BE591127 and BG274576, which mapped on the wheat homocelogous group 7, produced the specific bands for P. huashanica, H8911 99 and 12DH25. It demonstrated that the chromosome from P. huashanica had a homoeologous relationship with the seventh group. Consequentially, 12DH25 was a dwarf material of a wheat P. huashanica disomic alien addition line, which could be exploited as an intermediate material in wheat genetic and breeding programs.