| The Northeast and Yellow-Huai-Hai Rivers Valley are the top two soybean growing regions inChina. The annual soybean production in the above two regions occupied above three quarters of thetotal output in China. Although over1000soybean varieties were released in the two regions in thepast century, only approximate10percent of these varieties were widely planted. To identify the yieldrelated charcters, plant morphological and growth period traits,89soybean varieties released since1940s were grown in12sites located in Northeast and Yellow-Huai-Hai Rivers Valley during theyears of2009,2010and2011, respectively. In addition,63varieties were selected to evaluate thephoto-thermal responses, and125SSR markers related with yield, plant height, growth period, andquality were selected to identify genetic diversity of89soybean varieties. Furthermore, to combinedata mentioned about with related phenotype data, association mapping were operated to search forthe elite alleles in these varieties. The main results are as follows:1. Agronomic traits evolution of widely-planted varieties originated from different regions anddecades.The overall trait evolution trends of varieties were summarized as: the days to flowering shortedand the days from flowering to maturity prolonged; the plant height and branche number per plantdeclined; lodging resistance enhanced and yield increased. The yield increasement of varieties fromthe northern Heilongjiang was due to increased numbers of pods and seeds per plant, while that ofvarieties from the middle and south parts of Heilongjiang attributed to increased seed numbers perpod, however, the pod number per plant and100-seed weight changed a little. The yield enhancementof varieties from Jilin-Liaoning province was the result of increased100-seed weight; and that ofvarieties from Yellow-Huai-Hai Rivers Valley was also associated with100-seed weight increament,while pod and seed numbers per plant decreased significantly. The traits of varieties fromJilin-Liaoning provinces changed the least compared with that in other regions.2. Quality trait evolution of widely-planted varieties from different regions and decadesThe contents of protein and isoflavones increased as the orignated latitudes of varieties weregetting lower. The content of oil, Vitamine E and carotenoids of vatieties from the northeast weremore than that of varieties from Yellow-Huai-Hai Rivers Valley. The contents of linoleic acid,linolenic adid, statch, oligosaccharide, isoflavone and lectin of varieties from the north part ofHeilongjiang province increased significantly with the released years; the contents of linoleic acid,palmatic acid, total isoflavones of varieties from the middle and south parts of Heilongjiang provinceincreased significantly along with the released decades; the starch content of varieties fromJilin-Liaoning provinces increased with the year of release, the contents of oleic and stearic adids, andlectin of varieties from Yellow-Huai-Hai Rivers Valley increased significantly with the released year.3. Changes of photo-thermal response of widely-planted varieties derived from different regions and decadesThe photoperiod sensitivity (PS) under spring and summer sowing of the varieties from the northpart of Heilongjiang province and Yellow-Huai-Hai Rivers Valley decreased with the decades ofrelease, while the same index of varieties from middle and south parts of Heilongjiang provincedeclined under summer sowing. The temperature sensitivity (TS) under short day of varieties from themiddle and south parts of Heilongjiang province and Yellow-Huai-Hai Rivers Valley decreased withthe released year, while that under long day of varieties from Yellow-Huai-Hai Rivers Valleyincreased with decades of release. The ΔPS(PS difference of under different temperature), ΔTS(TSdifference under different photoperiod) and PTCS (photothermal comprehensive sensitivity) ofvarieties from Yellow-Huai-Hai Rivers Valley decreased. The PS, TS and PTCS of widely-plantedvarieties increased gradually with the decreasing of their original latitude, while ΔPSand ΔTSattainedopposite trends compared with the former ones. It showed that the PS, TS and PTCS of varieties fromsouth are more sensitive than that from the north of China, but the photothermal interactive responsesof varieties were opposite.4. The pedigree analysis of widely-planted varietiesBased on the collected pedigree data of the113soybean varieties, the end ancestors and directparents of the widely-planted varieties were traced. Compared to the data of the varieties reportedbefore, the number of end ancestors of widely-planted varieties was higher than the ordinary varieties,and their genetic bases were broader. Newly-bred widely-planted varieties have richer geneticbackground than the previous widely-planted varieties. Genetic basis of widely-planted soybeanvarieties from Yellow-Huai-Hai Rivers Valley are broader than that of ones from the northeast China.5. The genetic diversity of widely-planted soybean varieties from different regions and decadesThe average polymorphism information content of the varieties from the north part ofHeilongjiang province, south and middle parts of Heilongjiang province, Jilin-Liaoning province andYellow-Huai-Hai Rivers Valley were0.414,0.469,0.522and0.562, respectively. Except for thevarieties from the north part of Heilongjiang province, the varieties released after1980in the otherthree regions had higher PIC values than that of varieties released before1980. UPGMA-based clusteranalysis classified the tested varieties into three major groups, corresponding with the original placesof the varieties. The varieties from the northeast and Yellow-Huai-Hai Rivers Valley were classifiedinto two major groups respectively, except for Jidou12, a variety from the northern Yellow-Huai-HaiRivers Valley, which was classified into an independent group. In the northeast China, varieties ofHeilongjiang province were classified into one subgroup and the varieties from Jilin and Liaoningprovinces were into another subgroup, indicating that the widely-planted varieties from the sameregion were apparently homogenized.6. The exploitation of elite alleles of varieties from different regions and decadesAmong the SSR markers identified in this study, there were141loci associated with the24traits,39loci associated with the yield traits including yield, pods and seeds per plant and100-seed weight19loci associated with plant height, lodging index, the days to flowering and maturity, and82loci associated with the quality traits including protein, oil and isoflavones. The analysis on marker effectsand the identification of positive and negative loci and carriering materials showed that the extremeaccessions possessed the alleles with larger effects. |
PDF Full Text Request