大麦农艺性状的杂种优势与配合力分析

Analysis on Heterosis and Combining Ability of Agronomic Traits in Hybrid Barley

从中国不同大麦产区选取12份代表性的品种(系),按NCⅡ设计配制成35个杂交组合,对7个主要农艺性状,株高、穗下节间长、穗长、单株穗数、每穗实粒数、单株粒重、千粒重的杂种优势与配合力进行了分析,旨在为杂交大麦育种的亲本选配提供依据。结果表明,不同性状的中亲优势表现不同,株高、穗下节间长、穗长、千粒重大多为正向优势组合,所占比例分别为90%、73.3%、73.3%、73.3%;单株穗数、每穗实粒数、单株粒重多呈负向优势,其中每穗实粒数负向优势组合所占比例高达76.7%。同一性状不同亲本的一般配合力(GCA)不同,同一亲本不同性状的GCA不同,组合间的特殊配合力(SCA)也是如此。GCA高的两亲本所配组合的SCA并非一定高,SCA是相对复杂的基因互作结果。因此,在杂交大麦育种的亲本选配上,应先考虑GCA高的亲本,在此基础上,筛选SCA高的组合。

In order to provide a guideline in the selection of parents in hybrid barley breeding, twelve representative cuhivars （lines） from different barley production areas in China were hybridized according to NC Ⅱ design to form 35 crosses to analyze the heterosis and combining ability of 7 agronomic traits including plant height （PH）, internode length below spike （IL）, spike length （SL）, spikes per plant （SP）, kernels per plant （KP）, kernel weight per plant （KWP） and thousand kernel weight （TKW）. The results indicated mid-parent heterosis （MPH） of F1 presented to be diverse in different traits. Positive heterotic crosses were obtained in the traits of PH, IL, SL and TKW, the proportion of which were 90%, 73.3%, 73.3% and 73.3%, respectively. More negative heterotic crosses appeared in the traits of SP, KP and KWP, and the highest proportion of 76.7% existed in the trait of KP. Different parents had different general combining ability （GCA） in the same trait and the CCA of one parent varied in different traits. The special combining ability （SCA） among crosses has the same result as to the variation of GCA. The SCA of a cross derived from two parents both with high GCA may not be high, and is the consequence of the interaction of genes. Therefore, primary consideration should be placed on parents with high GCA and cross with high SCA can be then screened.