抗条锈病小麦-滨麦Lm#3Ns二体异附加系的分子细胞遗传学鉴定

滨麦(Leymus mollis)是小麦的三级基因源,具有改良小麦所需的许多优良性状。为了将滨麦中的优异基因导入到普通小麦中,通过远缘杂交获得小麦-滨麦异附加系、异代换系、易位系,以选自普通小麦7182与滨麦衍生后代M42(2n=54)F_6代的株系M11005-1-2-7-10-1-1(M11005A)为供试材料,对其进行了形态学、细胞学、原位杂交、分子标记、抗病性等综合鉴定。细胞学观察结果显示,M11005A有44条染色体且配对良好,可以稳定遗传。原位杂交及分子标记结果表明,M11005A含有42条普通小麦染色体和1对来自滨麦Lm#3Ns的染色体,并且用Oligo-pTa535探针得到了Lm#3Ns的FISH核型;筛选出6个EST及8个PLUG特异分子标记可以用来鉴定Lm#3Ns染色体,其中只有1个EST和4个PLUG标记可以同时在M11005A中扩增出滨麦和华山新麦草的条带,说明滨麦的Lm#3Ns染色体与华山新麦草的3Ns基因组之间存在差异。M11005A的穗长、穗型、小穗数、千粒重与亲本7182无显著差异,但分蘖数较7182显著增加,株高显著降低。抗条锈病鉴定结果显示,苗期M11005A对条锈菌生理小种CYR29和CYR34表现高抗,对CYR32表现高感,成株期对CYR32和CYR33混合小种表现高抗,推测滨麦的Lm#3Ns染色体携带对CYR29和CYR34小种的抗性基因,又携带了成株期对CYR32和CYR33的抗性基因。因此,M11005A可以作为抗源应用于小麦的条锈病抗性改良中。

Molecular Cytogenetics Identification of a Wheat-Leymus mollis Lm#3Ns Disomic Addition Line with Resistance to Stripe Rust

Leymus mollis is a tertiary gene source of wheat with many excellent traits that could be used in wheat improvement. In order to introduce the superior gene in L.mollis into common wheat,the wheat-L.mollis addition lines,substitution lines,and the translocation lines were obtained by distant hybridization. Line M11005-1-2-7-10-1-1(M11005A) is bred from F₆ generation of the crossing between common wheat cultivar 7182 and wheat-L.mollis derived line M42(2n=54).M11005A was comprehensively identified by morphology,cytology,in situ hybridization,molecular marker,and disease resistance. Cytological observations showed that M11005A has 44 chromosomes with normal pairing and stable inheritance. In situ hybridization and molecular markers results showed that M11005A contained 42 common wheat chromosomes and 1 pair of chromosomes from L.mollis Lm#3Ns. And Lm#3Ns FISH karyotype was obtained by Oligo-pTa535 probe. Screening 6 ESTs and 8 PLUG-specific molecular markers can be used to identify Lm#3Ns chromosomes. Only one EST and four PLUG markers can amplify the bands of L.mollis and Psathyrostachys huashanica in M11005A simultaneously. This indicated that there is a certain difference between the Lm#3Ns chromosome of L.mollis and P.huashanica. Agronomy evaluation showed that there were no significant differences in morphology,such as spike length,panicle type,spikelets and 1 000-grain weight between M11005A and parent 7182. However,M11005A''s tiller number and plant height were respective significantly higher and significantly decreased than those of 7182. The results of stripe rust resistance identification showed that M11005A showed high resistance to CYR29 and CYR34,but high sensitivity to CYR32 in seedling stage. While it had high resistance to CYR32 and CYR33 mixed races at the adult plant stage. It is estimated that the Lm#3Ns chromosome carries resistance genes to CYR29 and CYR34 races,and also carries resistance genes to CYR32 and CYR33 in the adult stage.Therefore,M11005A can be used as a potential source in the improvement of stripe rust resistance of wheat.