The Effect Of Leaf-Cutting And Spikelet-Thinning On Rice Quality And The Relationship Between Rice Quality And Leaf- Spikelet Ratio

Source-sink theory has a closely associated with rice quality. Rice leaf area of single stem and number of spikelet per panicle at flowering stage are two important indicators of source-sink in rice. Previous studies mainly focused on the effects of those two indicators on rice grain filling, but few of them studied the effects of leaf area of single stem and number of spikelet per panicle on rice qualities. Effects of leaf-cutting and spikelet-thinning treatment on the formation of rice quality were investigated and relationship between rice quality and the leaf-spikelet ratio was studied. The main results were shown as follows:(1) Milling quality:Results indicate that increased leaf-cutting number induces a decrease of leaf-spikelet ratio and significant increases of chalky grain rate and chalkiness were obtained. Moreover, when leaf-cutting number decreased, leaf-spikelet ratio was increased and chalky grain rate and chalkiness were significantly decreased. Our study initially identified that The critical value of interval of Leaf-spikelet ratios were 1.36 and 1.64 cm2/spikelet.(2) exterior quality:Results indicate that increased leaf-cutting number induces a decrease of leaf-spikelet ratio and significant increases of Brown ric、Milled rice and Head milled rice.Moreover, when leaf-cutting number decreased, leaf-spikelet ratio was increased and Brown ric、Milled rice and Head milled rice were significantly decreased. Our study initially identified that different level of chalky grain rate and chalkiness generates different leaf-spikelet ratio. Leaf-spikelet ratios at chalky grain rate and chalkiness of=10% and=1.0%,=20% and=3.0%,=30% and=5.0% werel.5、0.9、0.7 cm2/spikelet and2.3、1.2、0.8cm2/spikelet.(3) cooking quality:Results indicated that increased numbers of the leaf-cutting induced the decreased leaf-spikelet ratio while Pkv, Hpv and cpv were significant increased. Moreover, when the numbers of the spikelet-thinning increased, leaf-spikelet ratio increased but Pkv, Hpv and cpv were significantly decreased. And the relationship between BDV, SBV,CSV and the leaf-spikelet ratio were complexed. Our study initially identified that The critical value of interval of Leaf-spikelet ratios were 1.5-3.0 cm2/spikelet.The relationship between amylose content, gel consistence and the leaf-spikelet ratio were studied based on different treatment and results indicated that increased numbers of the leaf-cutting induced the decreased leaf-spikelet ratio while amylose content were significant decreased and gel consistence were significant increased. Moreover, when the numbers of the spikelet-thinning increased and gel consistence were significant decreased, leaf-spikelet ratio increased but amylose content were significantly increased. Our study initially identified that the critical value of interval of Leaf-spikelet ratios were 2 cm2/spikelet.(4) nutritional quality:Results indicate that increased leaf-cutting number induces a decrease of leaf-spikelet ratio and the relationship between nutritional quality and source-since theroy were complex.