The Correlation Between The Changes Of Root Bleeding Sap And Photosynthetic Characteristics Along With Material Production In Rice Cultivars Of Different Years

There have been many researches about photosynthetic physiological ecology of rice above-ground, but study of the relationship between roots and above-ground of rice was indeterminate. Aim to understand the changes of root activity bleeding sap weight (BSW) and its correlation between root activity with organ biomass above-ground and leaf photosynthesis during the genetic improvement. In this study, the sample of33rice varieties bred from1958to2005were used to research BSW, organ biomass above-ground, leaf net photosynthetic rate (PN), released years, yield, Wish to investigate the limitation and mediation come from roots to leaf photosynthesis, and provide a theoretical basis for improve photosynthetic production ability and high yield cultural practice in rice.Research work was conducted in rice experiment field of Jilin Agricultural University in2010and2011. BSW, organ biomass above-ground (single stem, leaves, stem and sheath, panicle), net photosynthetic of different cultivars rice were measured at booting, heading,10days after heading,20days after heading and30days after heading. The result as follows:1. Change of BSW and organ biomass in old and new rice cultivars at different growth stagesRoot BSW becomes higher from boot stage to10DAH, and reaches maximum at10DAH, then becomes decline, and to minimum at30DAH. The BSW of new cultivars was higher than that of old cultivars obviously. The single stem biomass and stem and sheath biomass increased obviously in both old and new cultivars from10DAH, and new cultivars kept continuous growing. The leaf biomass in new cultivars was higher than that of old cultivars at different stages, and reached significant correlation at20DAH. It showed that photosynthetic capacity of new cultivars was higher than that of old cultivars. The panicle biomass was higher than that of old cultivars from heading to the ripening period, and reached significant correlation at10DAH.2. Relationship between biomass of rice cultivars at different growth stages and root bleeding sap weightThe BSW at heading and10DAH were significant positively correlated with single stem, BSW at10DAH was significant positively correlated with leaves biomass, BSW at heading was significant positively correlated and it was strong significant correlation at10DAH with stem and sheath, and BSW was significant positively correlated with panicle at10DAH and20DAH. It showed that the relation between root activity and organ biomass in10DAH was the closest, and the contribution of panicle to root was the greatest.3. The relationship between rice BSW and released years, leaf PN and yieldThe BSW was significant positively correlated with released year at10DAH in these two years. The relationship between BSW and released year at boot stage,20DAH,30DAH were not reached significant level. The BSW was significant positively correlated with PNat10DAH,20DAH. The genetic improvement of rice cultivars led to apparent increase of root BSW and PN. The relationship between BSW and yield in two years was significant at10DAH, its relationship between BSW and yield at boot stage, heading,20DAH,30DAH were not reached significant level.4. The relationship the ratio of BSW and organ biomass with released year at10DAH.The ratio of BSW and leaf was positive correlation, but not significant. The ratio of BSW and stem and sheath, that of BSW and panicle, that of BSW and single stems were negative correlation with released year. This result showed that root and above-ground parts were coordinated evolution in genetic improvement of rice cultivars.Our results with were showed, root BSW becomes higher from boot stage to10d after heading (10DAH), and reaches maximum at10DAH, then becomes decline, and to minimum at30DAH. The genetic improvement of rice cultivars led to apparent increase of root BSW, PN and the biomass of each organ above-ground. Correlation of root BSW at10DAH and the biomass of each organ above-ground was significant positive. Correlation of BSW and photosynthetic rate of leaf along with production were all significant positive. BSW of10d after heading could be used as an index of PN and high yield.