Studies On The Elastic Modulus And Tensile Breaking Point Of Rice Internodes And Related Characters

Lodging had impact on the yield and qulity of rice. Breeding for dwarfnessenhanced the ability for lodging resistance and economical coefficient. But the biologicalyield wasn't changed much. The breakthrough must happend in the biological yield, ifthe yield was enhanced,when the yield achieved a certain level. One of important waysfor increasing biology yield was increasing plant height, but it brought the danger oflodging.The factors except plant height become important research content. Stalkphysical property is the major factor which effected the ability for lodging resistance,the stalk's mechanical strength is the most important index for breeding selection. Thisexperiment selected five varieties (lines) which displayed stronger lodging resistance infield. The elastic modulus, the tensile breaking point of Early and Late Rice wereinvestigated. Biological yield of rice in different stages were also investigated.And thenthe significance test, Multi-comparison and the correlation analysis were carried out.The result indicated:The elastic modulus and the tensile breaking point of the different internodes in thesame variety (line) were usually in the following order: the second internode＞the thirdinternode＞the fourth internode, and their differences were significant or not dependedon the variety (line) and the development stage. The same internode of different variety(line) had different elastic modulus and tensile breaking points, their differences weresignificant or not depended on the position of internode,the development stage and the genetic composition.The elastic modulus and the tensile breaking point of the internodes were negativelycorrelated with its wall section area, diameter and wall thickness of the internode. From15 days after full heading to maturity,the growing stage had limit influence on the elasticmodulus and the tensile breaking point. Physical property of interuode achieves stablelevel at 15 days after full heading.From heading to maturity, the weight of the panicle was rising, accumulation ofDry Matter mainly happened in the panicle, Compared with the accumulation of DryMatter in the panicle, the accumulation of Dry Matter in the leaf,sheath and culmchanged litte.The resultes of analysis on the correlationg between stalk's physical property andthe accumulation of Dry Matter indicated that stalk's physical property of early ricewere positively correlated with its Dry weight of sheath. In late rice, Physical propertyof 3rd an 4th internode were. also positively correlated with its Dry weight of sheath.The dry weight of Leaf sheath occupied not a small part in the dry weight of whole plant.The sheath had a big influence on stalk physical property. It's a vital Significance forenhancing the stalk's mechanical property to optimizate the structure of leaf, sheathand culm.Total grain per panicl and Full grain per panicle were negatively correlated withthe Dry weight of leaf,sheath, culm, panicle and whole plant. 1000 grain weight and NO.of effective panicle per hole were positively correlated with the Dry weight of leaf,sheath,culm, panicle and whole plant. Panicle length of Early Rice were positively correlatedwith the Dry Weight of leaf,sheath, culm, panicle and whole plant, but Correlationcoefficients didn't achieve the significant level. Panicle length of Late Rice werenegatively correlated with the Dry Weight of leaf,sheath, culm, panicle and wholeplant.Correlation coefficients achieve the significant level.