不同谱系节节麦的杂种优势分析

节节麦含有丰富的优良基因,可用于小麦的品质改良和产量提高。为了揭示L1和L2谱系节节麦的遗传差异和杂种优势,对L1、L2谱系节节麦开展人工杂交,采用SSR分子标记鉴定杂种F1的真实性,对其花粉活力和F1减数分裂时染色体配对情况进行观察,并对其主要农艺性状进行了调查和统计分析。结果表明,长期的地理隔离使L1和L2谱系节节麦产生一定的遗传分化,但尚未形成生殖隔离。F1的花粉活力和同源染色体配对正常,绝大部分F1的中期同源染色体联会形成环状染色体,少数出现棒状染色体。对8个杂交组合的16个主要农艺性状的统计分析表明,L1、L2谱系节节麦的百粒重和分蘖数存在杂种优势,尤其是杂交组合AY26×AY46和XJ47×AY46,其百粒重(IH>143%,OPH>21%)和分蘖数(IH>187%,OPH>57%)存在显著的杂种优势。有望通过对这2个杂交组合的进一步深入研究,揭示节节麦杂种优势的分子机理,为其在小麦产量育种中的有效利用奠定基础。

Heterosis Analysis of Aegilops tauschii among Different Lineages

Aegilops tauschii,the D genome donor of common wheat,contains abundant advanced genes which can be used to improve the quality and yield of wheat.In order to discover the genetic difference and heterosis of Aegilops tauschii between L1 and L2 lineages,the authenticity of the hybrid F1,pollen vigor,chromosome pairing at meiosis and the main agronomic traits were investigated based on the artificial hybridization.The results showed that long-term geographical isolation resulted in significant genetic differentiation of the L1 and L2 lineages but without reproductive isolation.The pollen vigor and homologous chromosome pairing of F1 are normal.Most of the F1 metaphase homologous chromosomes formed circular chromosomes with a few rod-like chromosomes.Based on the statistical analysis oF16 major agronomic traits in 8 cross combinations,significant heterosis were found in the yield traits:hundred grain weight and tiller number,especially in the hybrid combinations AY26×AY46 and XJ47×AY46(hundred grain weight:IH>143%,OPH>21%;tiller number:IH>187%,OPH>57%).Therefore,further research is expected to reveal the molecular mechanism of Aegilops tauschii heterosis among the two hybrid combinations,which will contribute to the heterosis utilization for high-yield breeding in common wheat.