The Effect Of Wheat Flag Leaf To The Photosynthesis And Yield And The AFLP Marker Of Flag Leaf Gene

The wheat flag leaf is the most important photosynthetic organs for wheat grain production.It has been known that the ablity of photosynthesis is related to vertical shape of flag leaf. In present study, using wheat lines 2-26 and H420 with vertical shape and inverted shape of flag leaf, respectively, and their hybrid progenies as materials, net conduct photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) were tested, and the main yield charaters were also counted. The effects on photosynthetic characteristics and yield with different shapes of the flag leaf were analyzed. The result showed that different shapes of wheat flag leaf have different influence on photosynthetic characteristics. Net photosynthetic rate (Pn), stomatal conductance (Gs), and intercellular CO2 concentration (Ci) of the vertical shape of flag leaf on average was lower than that of inverted shape of wheat flag leaf, Transpiration rate (Tr) of the vertical shape of flag leaf on average was higher than the inverted shape of wheat flag leaf. No significant differences in all Photosynthetic characteristics were founded in two different shapes of flag leaves (P> 0.05). In the three factors of forming wheat production, the wheat spike number and 1000-kernel weight of inverted shape of flag leaf were higher than that vertical flag leaves of wheat, grains per spike of vertical flag leaf was higher than the inverted flag leaves of wheat. Significant differences for grains per spike and 1000-kernel weight, and not significant difference for sipke number between two flag leaves of different shapes were observed. It showed that other factors except the shape of flag leaf had relations during the forming of wheat yield for example, For example, theory of the Origin and flow Library, length of flag leaf, width, leaf area, characters of wheat group clover canopy and their photosynthetic capacity and so on. Therefore, the shape of the flag leaf of wheat affecting on wheat yield need further study.The gene with vertical shape of wheat flag leaf was primary also maked adopted wheat line H420 with inverted flag leaf and 2-26 with vertical flag leaf and the F2 generation including 224 plants between H420×2-26 as materials by the AFLP technology. The results showed that there was one pair gene to control the vertical and inverted shape of flag leaf in the two different parents. The vertical shape of flag leaf was dominant.96 primer combinations in the 2-26, H420 and inverted flag leaf gene (+) pool and vertical flag leaf gene pools (-) were polymorphic among 304 AFLP primer combinations of randomly selected, the polymorphism rate was 32%. We used again the parents and gene pools and randomly selected five different plants from F2 generation to selected 96 primer combinations with polymorphism, eight primer combinations showing stability polymorphism among them. However,224 plants from F2 generation of H420×2-26 was used to further select for 8 primer combinations, only one primer combination, Pstl-TAG/Msel-CGA produced 220bp specific fragment to link the gene of the flag leaf was obtained. Linkage analysis by using Mapmarker3.0 software, the genetic linkage distance of specific fragment produced by Pstl-TAGIMsel-CGA to gene was 8.1 cM. It provided a good foundation for utilizing molecular marker to select high yield wheat and transgenic varieties in breeding programs.