Studies On The Genetic Diversity Of Wheat (Triticum Aestivum L.) Cultivars In Hebei Province

In order to learn the genetic diversity of wheat cultivars in Hebei province released from 1960s, methods based on agronomic traits, seed storage proteins and DNA molecular markers (SSR), were employed to investigate the 118 cultivars collected. The main results were as follows:1. There was a relatively wide variation in agronomic traits, the sterile spikelet number had the greatest coefficient of variation, and the second was the tiller numbers per plant. The smallest coefficient of variation was the spikelet number.With the partial correlation coefficients, had nine pairs character assumed significantly positive correlations and four pairs character assumed significantly negative correlations. According to principal compolent analysis, the first five main compolent made the contribution of 87.23% to variation.2. Acid polyacrylamide gel electrophoresis (A-PAGE) was used to detect genetic variation of seed gliadins in 118 wheat cultivars of Hebei Province in nearly 40 years. These cultivars were chosen for their prominency at different breeding history in this province. The results showed that 101 bands were separated, giving a total of 118 gliadin combinations for the cultivars tested. Furthermore, the 101 bands could be divided into four zones, i.e.α,β,γandωzones. Fifteen bands and 87 band combinations were present in a zone, 24 bands and 110 combinations inβzone; 21 bands and 90 combinations inγzone, and 41 bands and 111 combinations inωzone, respectively. The genetic similarity (GS) based on gliadins ranged from 0.043 to 0.86, with an average of 0.35. Cluster analysis based on genetic similarity of seed gliadins indicated that 118 cultivars studied could be classified into 7 clusters at the level of GS 0.354.3. Twenty pair of simple sequence repeats (SSR) primers were used to study the genetic diversity of 118 registered wheat cultivars of Hebei Province. The results showed that the 20 pairs of primers produced a total of 79 polymorphic amplified fragments. The average number of alleles per SSR locus was 3.95, ranged from 2 to 7. The polymorphism information content (PIC) of the SSR loci varied from 0.45 to 0.92 with an average of 0.74. Genetic similarities among the 118 cultivars ranged from 0.095 to 0.954 with an average of 0.545. The cluster analysis divided the cultivars into 12 groups. 4. The comparison of clustering results of agronomic trait, gliadin and SSR showed that they were not always agreed well.The materials were classified as eight groups according to the cluster analysis of agronomic traits. The genetic distance(GD)based on three methods assumed significantly positive correlations.Comprehensive analysis the genetic diversity of wheat cultivars in Hebei province, can be found that the genetic diversity from the 1960s to the 1990s becomes bigger, and then declined slightly.