The Genetic Diversity Of Shaanxi Wheat Landraces

Wheat landraces are the specific resources with a long history and different types in Shaanxi. They have strong adaptability to the local environment and production potential undergone natural selections. Therefore, their potential utilization is of great importance. In this article, analysis of the gene-resources of wheat landraces and evaluation of the genetic diversity on morphological, biological and molecular levels were conducted by these basic research which is beneficial to discover the desirable genes and transfer them into other varieties to promote the genetic diversity of cultivars. The main results were as follows:1.Seven morphological and three agronomic traits of 1225 wheat landraces which have were from Northern Shaanxi,Guanzhong,Southern Shaanxi area were investigated and computed.The results show that there are abundant genetic diversity in seven morphologic characters ,three agronomic characters and two diseasetraits of Shaanxi wheat landraces .There are higher genetic diversity indexes(H/)in plant height, 1000-grain weight and glume colour in Landraces from Northern Shaanxi; higher genetic diversity indexes(H/)in kernel number ,kernel color,ear type and scab in landraces from Guanzhong,and higher genetic diversity indexes ( H/ ) in winter and spring ,mature date,awn length,grain hardness,stripe rust in landraces from Southern Shaanxi.These are the important characteristics in genetic diversity of Shaanxi wheat landraces.2.The diversity among 1036 wheat landraces was evaluated by employing the method of SDS-PAGE. The results showed that the composition of HWM-GS had distinctive Characteristics. It showed that:(1) At the Glu-Al locus, the frequency of null subunits (Gul-A1c)was highest( 97% ), indicating that it was a significant subunit. The 2* subunit was rare, only 0.19%. (2) At the Gul-B1locus, 7+8 subunit occupied almost( 84.7%). The High-quality subunits 14+15,23+24 related with quality and rare subunits 7*(0.19%),6+8*(0.58%)and 7*+8(0.19%)were observed in the materials.(3) At the locus Gul-D1t, the frequency of subunit 2+12(Gul-D1c)(96%) was higher and that of desirable subunit 5+10 was only 0.39%.Predominant variation was exhibited at each locus. At the the Glu—A1 locus, it was null subunit; At the Glu-B1 locus, it was subunit 7+8; At the Gul-D1 locus, it was subunit 2+12; 5+10,2* and 7+8 was 0.39%, 0.19%, and 84.7% respectively. Therefore, these materials containing desirable and scared subunits could be used as basic materials in the germplasm resources and offer more choices for breeders.3.By employing the methods of morphology, HWM-GS electrophoresis and SSR, the research were conducted on the cultivars shared the same name among the wheat landraces in Shannxi. It was found that among Sanyuehuang , S481,S487,S492 from Baishui was the same material, and S890,S900,S905 from Shangnan, S449,S465,S469 from Pucheng was the same material. It remained to be seen whether S413 and S 414 was the same material. It was also found that among Laohongmai, S373 and S375 from Taibai, S548 and S494 from Baishui was the same material. Among Hongmangmai, S960 and S983 from Shanyang, S260 from Fuxian was the same material.4.The agronomic traits were investigated and analyzed, and the genetic diversity among Turgidum wheat was evaluated by using HWM-GS and prolamine electrophoresis. Analysis of the main agronomic traits showed that there was abundant variation among 9 traits of 24 wheat landraces. Some materials characterized by lower plant height, more panicles and seeds were found; 1000-grains weight of 16.7% of 24 Turgidum wheat landraces reached more than 40g. In addition, scared subunit 3, 4 and the combination of scared subunit null,14+15,2 and null,14+15,4 were found when HWM-GS electrophoresis was conducted. Special subunit, Gul-B1-Ⅲat the Glu-B1 locus, its frequency reaching 45.8%,was detected. Prolamine electrophoresis showed that the types of patterns of prolamine exhibited polymorphism among 24 Turgidum Wheat. 48 types of patterns with different Rf were observed and 360 bands were observed in each pattern. There was difference inα,β,γandωregion among these bands, indicating that there was extensive mutation in alleles, that was to say, there was polymorphism in the gene locus which encoded the prolamine.