| Henan is one of important zone of planting wheat (Triticum aestivum L.) of china.1048 landraces were protected in Henan. Historicaly, wheat landraces have made tremendous contributions to breeding and production of wheat.Chinese wheat landraces possess many useful genes for wheat improvement. For example, gene Pm24 from `Chiyacao' is efective against a wide range of powdery mildew isolates. "Wangshuibai" can be one of the best sources of resistance to Fusarium head blight.Absence of Wx gene effecting the quality of starch and noodle processing was obtained from landrace . "Tutoumai" is one of the best sources of resistance to pre-harvest sprouting.The deployment and utilization of disirable genes from landraces are important in development of modem wheat cultivars. In the present study, gliadin composition and SSR (also known as microsatellite) technique were used to detect genetic diversity of Henan wheat landraces that originated from various wheat growing regions.There are 1048 wheat landraces in this study, rulating to whole Henan. Five seeds from each accession were crushed to analyze gliadin composition using acid polyacrylamidegele lectrophoresis. 5240 kernels were studied. 682 homogeneous materials were surveyed and germinated.21 materials did`t germinate.The other 661 material germinated and the bulked leaf samples were used to extract DNA to be used in SSR analysis. The microsatellite primers used in this study detects 9 loci located on 7 chromosomes.(1) The results from gliadin analysis indicated that 88 gliadin bands were observed in a total of 5240 kernels from 682 accessions.Among them,ω- ,γ-,β- andα-zone had 24, 25 , 21, and 18 bands, respectively, which formed 630 banding patterns. The number of bands within an accession ranged from 13 to 26. The polymorphism of gliadin banding patterns was observed among accesions and within an accession. 682 accessions (65.1%) were identical in gliadin banding patterns among diferent kernels within each accession. The remaining landraces display edvariation in their gliadin paterns among kernels within an accesion. The homogeneous accessions with genetic distance o were observed with different name accessions and with some name accessions, and their agronomic characters were observed resembly. Then their were ascertained homogeneously. The total genetic diversity index the accessions tested was 0.981. The genetic diversity index forω-,γ-,β-, andα-zone was 0.873,0.904,0.835,0.814 , respectively .The average genetic distance among all accessions was 0.442, ranging from 0 to 0.94. The average frequency among all accessions was 22.63%, ranging from 0.15% to 98.83%. There was not relativity between the genetic diversity of 682 Henan wheat landraces and their zone.(2) Microsatellite analysis indicated that 247 aleles were detected with an average of 27.4 and a range of 23 to 41 for each primer pair. Cluster analysis indicated that the wheat landraces were diferentiated using the 9 primer pairs used. More accessiongs with genetic distance 0 were observed . The total genetic diversity index the accessions tested was 0.987. The genetic diversity index fof each primer was 0.894,0.870,0.908,0.918,0.922,0.890,0.872,0.914,0.901, respectively .The average genetic distance among all accessions was 0.712, ranging from 0 to 1.52. The average frequency among all accessions was 12.93%, ranging from 0.15% to 81.69%. There was not relativity between the genetic diversity of 661 Henan wheat landraces and their zone.(3) Comparison between gliadin banding patterns and SSR analysis indicated that the accessions with genetic distance 0 by SSR was more than those by gliadin. Both methods produced similar total genetic diversity.They were 0.981 based on gliadin and 0.987 based on SSR. The range and average of genetic distance based on SSR analysis were greater than those based on gliadin banding patterns. The range and average of frequency based on gliadin banding patterns were greater than those based on SSR analysis. The genetic diversity based on glisdin and SSR was 0.990.The clustering results based on gliadin and SSR analyses were not always agreed well, which might be due to diferent genetic information of chromosome and loci as determined by each method. Based on the results from the presents study, we concluded that: (1)The results of gliadin composition analysis indicated that a high percentage of Henan wheat landraces are genetically heterogeneit populations that are composed of individuals with diferent gliadin composition; (2) Based on the genetic heterogeneity of wheat landraces, a largepopulation should be considered in order to maintain the genetic completeness during their collection and conservation; (3) Gliadin and SSR indicated that some accessions were homogeneit with same name , some accession were heterogeneit with same name, some accessions were homogeneit with different name.The homogeneit accessions which were ascertained would be incorporated for managing and using germ plasm easily; (4) Some bands with low frequency were observed based on gliadin and SSR.We will study more for their biology significance. They also indicated that Henan wheat landraces are rich in genetic diversity and are potentially useful in wheat improvement. (5)The genetic diversity of Henan wheat landraces has no concern with zone. |
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