Research On Wheat Agronomic Traits And Genes Related To Developmental Stability

Wheat offers a large number of protein and energy for mankind, however, its stability has been affected by the current climatic fluctuation. There exists some certain relevance among wheat agronomic traits in terms of development; as climate fluctuates, how these agronomic traits coordinate development is still unclear. Interaction of genes and environment influences reproductive and developmental features. Vernalization genes, photoperiod genes, and genes related to flowering affect the development of wheat, while their influence on the stability of reproductive development is still not clear. Xiaoyan 81 has stable growth and development characteristics; while Xinong 1376 is strongly influenced by the climate. Using Xiaoyan 81 and Xinong 1376 as parents, the author built the RIL containing 208 families. The author chose 180 species of main wheat cultivars in major domestic wheat growing areas as well as RIL obtained from Xiaoyan81 and Xinong1376, as materials and sowed them by stages with time difference of 40 d in Yangling and Xingyang from 2012 to 2014, to study the correlation of agronomic traits in the aspect of development. From 2011 to 2014, the author planted wheat materials in major domestic wheat growing areas of 366 copies as materials in experimental fields in Yangling, Xingyang and Heze. To explore genes related to wheat developmental stability, using these planted materials of all the 366 copies as materials, and applying molecular markers to detect vernalization and photoperiod genes, the author probed the influence of vernalization and photoperiod genes on reproductive development, the stability evaluation criteria of which was number of day discrepancy of heading stage based on two different sowing periods. The author also gave cloning and sequencing studies to 2coding regions of TAPHS1 genes which are related to flowering and pre-harvest sprouting among 86 copies of varieties, probing the relation between number of day discrepancy of different sowing stages and sequence polymorphism of TAPHS1 genes.The researching results of this experiment were as follows:1 In the aspect of reproductive and developmental stability, there exists extremely obvious positive correlationbetween effective panicles per unit area and grain number; while there exists obvious positive correlation between effective panicles per unit area and spikelet number. Grain number shows extremely obvious positive correlation with flag leaf length and heading stage, and it also shows obvious positive correlation with peduncle length.Stability ofheading stage can be used as evaluation criteria of reproductive and developmental stability.2 Vernalization and photoperiod genotypes such as vrn-A1+vrn-B1+vrn-D1+Ppd-D1 acan maintain the reproductive and developmental regularity of wheat.Vrn-A1 causes reproduction and development to show extremely unstable characteristics; vrn-B1 can maintain the reproductive and developmental regularity of wheat to the greatest extent, while both dominance and recessiveness of photoperiod gene don’t show obvious influence on reproductive and developmental regularity.3 TAPHS1 gene contains 5 different kinds of polymorphism, which are named as type A,type B, type C, type D and type E. There exists large difference among the distribution of each polymorphism, with type A ranking the highest of 36.05%. Both polymorphism of Type D and E can enable wheat to obtain stable reproductive and developmental characteristics,type D being the best. In type D and E, the mutation of the single base A-G in the coding region results in that encoded Lys changes to Arg. What’s more, insertion or deficiency of base in the noncoding region of polymorphism of type D may subtly adjust reproductive and developmental stability.4 The author developed two pairs of molecular markers to detect the molecules of polymorphism of type D, using the first pair of primers to amplify: the target fragment of type D is 278 bp, smaller than the amplification results of other polymorphic materials by 8bp or10bp; using the second pair of primers to amplify: the target fragment of type D is 374 bp,larger than the amplification results of other polymorphic materials by 8bp, 10 bp or 14 bp.Among 288 copies of domestic materials, the author detected 53 copies containing type D,which showed obvious discrepancy with other materials without type D. Among 53 copies of materials with polymorphism of type D, 6 copies have large heading stage difference. Further analysis was given and the result showed that most of these materials with large heading stage difference are spring materials or partial spring materials, the reproductive and developmental stability of which may have been affected by vernalization gene.