Research On The Thickness Of Wheat Leaves

Leaves are the major organs that carry out photosynthesis duringwheat growth, particularly in seeds filling stage. The strength of thephotosynthesis is correlated with the structure of leaves that the strongerphotosynthesis capability of the leaves, the more nutrient substance couldbe reserved. Although numerous reports about the relationship betweenyield and the characters of flag leaf such as length, width or area wererevealed, few papers have demonstrated the correlation between thethickness of the flag leaf and wheat production. On the basis of formerresearches, this work uses ten varieties with quite differences of wheatflag leaf as materials to comparing their variance in photosynthetic rate,chlorophyll content, mesophyll cells form, the number of chloroplast,pore size, the number and area of vascular bundle etc., through bladethickness measuring instrument, portable photosynthesis system, SPAD,fluorescence microscope, cell segregation and freehand section and so on.The aim of these investigations is to shed light upon whether sunlight hasan effect on the production between thickness and diverse structures ofleaves.The results showed that there are differences between differentvarieties of wheat blade thickness, the difference in differentdevelopmental stages of one genotype has the trend of thickening first then thinning, different leaf blade thickness has significant difference ineach period that flag leaf less than second upper leaf that less than thirdupper leaf, Diurnal variation of flag thickness of wheat tends to thin astime goes on, and the flag leaf thickness is significantly positively relatedwith net photosynthetic rate, stomatal conductance and transpiration rate,but has no significant correlation with intercellular CO2concentration,with grouting time going, chlorophyll content shows the trend ofincreased first then fall down and the flag leaf has significant positivecorrelation with chlorophyll content.In order to study the relationship between inside anatomicalstructure of flag leaf and the thickness of flag leaf, we select fourthickness varied varieties as experimental material from ten, and theresult shows that different polycyclic cells have seen in wheat flag leavesthat especially tricyclic cells and tetracyclic ring cells, the more the bladethickness, the lower the number of mesophyll cells rings, flag leafthickness has significant negative correlation with the total width oftetracyclic mesophyll cells and has quiet negative correlation with thelength of them. The number of chloroplast cell ring increases with the cellrings increasing in tricyclic and tetracyclic mesophyll cells of the flagleaves in the four varieties. The thickness of flag leaf has the negativerelation with the length of stomatal and width, and has positivecorrelation with center vascular bundle circumference and crosscutting area and vascular bundle number.Furthermore, there is a correlation between thickness and yield ofwheat flag leaf that the thickness of flag leaf has extremely significantcorrelation with thousand-grain weight, grain number and weight of ear.To sum up, in this work we do a more comprehensive and objectivestudy of the structure of flag leaf, and analyze the relation between theirstructure, photosynthetic capacity, and production. The experimentproved that the thickness of the flag leaf has a great influence on yield.And in the process of breeding, we should select the relatively large bladethickness that can improve the yield of wheat.