Abstract: Analysis of genetic diversity changes in cultivated crops plays an important role in plant breeding.To understand the genetic diversity of bread wheat cultivars released in Henan province,Hebei province,Shandong province and Shaanxi province,genetic diversity of a total of 42 wheat cultivars which were registered in Huang-huai-hai area from 1992 to 2008 was analyzed based on nine agronomic traits.The results showed that among the nine agronomic traits tested,number of sterile spikelets has the largest variation with a coefficient of variance(CV) of 61.39%,effective tiller number and grain number per spike followed,while number of thousand-grain weight has the smallest variation with CV of 6.06%.Genetic diversity index(H′) of Henan,Hebei,Shandong,Shaanxi provinces are 1.83,1.82,1.73 and 1.62,with an average value of 1.75.Based on longest distance(Euclidean distance) method,all the cultivars can be clustered into three major groups,while the discrepancy of the second group cultivars and the third group cultivars was not distinct.It indicated that though the diversity of wheat has been improved in recent years,it is necessary to further broaden the genetic basis for breeding needs.On character selection,it is very important to select the characters with obvious coefficient of variance;and on breed selection,we should pay more attention on selecting the breeds with high yield,high grain weight per plant and high grain number of single plant.

Key words: Wheat(Triticum aestivum L.), Agronomic trait, Genetic diversity

CLC Number: 

• S512.03