Superior grains determined by grain weight are not fully correlated with the flowering order in rice  

作　　者：PENG Ting L Qiang ZHAO Ya-fan SUN Hong-zheng HAN Ying-chun DU Yan-xiu ZHANG Jing LI Jun-zhou WANG Lin-lin ZHAO Quan-zhi 

机构地区：[1]Collaborative Innovation Center of Henan Grain Crops,Henan Agricultural University [2]Research Center for Rice Engineering in Henan Province,Henan Agricultural University [3]College of Agronomy,Henan University of Science and Technology

出　　处：《Journal of Integrative Agriculture》2015年第5期847-855,共9页农业科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(31271651);the projects from Rice Industrial Technology System in Henan Province,China(S2012-04-02)

摘　　要：Rice panicles are composed of many branches with two types of extreme grains,the superior and the inferior.Traditionally,it has been well accepted that earlier flowers result in superior grains and late flowers generate inferior grains.However,these correlations have never been strictly examined in practice.In order to determine the accurate relationship between superior and inferior grains and the flowering order,we localized all the seeds in a panicle in four distinct rice species and systematically documented the rice flowering order,flower locations and the final grain weight for their relationships.Our results demonstrated that the grain weight is more heavily determined by the position of the seeds than by the flowering order.Despite earlier flowering has a positive correlation with the grain weight in general,grains from flowers blooming on the second day after anthesis generally gained the highest weight.This suggests earlier flowers may not result in superior grains.Therefore,we concluded that superior and inferior grains,commonly determined by grain weight,are not fully correlated with the flowering order in rice.Following the order of the grain weight,the superior grains are generally localized at the middle parts of the primary branches,whereas inferior grains were mainly on the last two secondary branches of the lower half part of the panicle.In addition,the weight of inferior grains were affected by spikelet thinning and spraying with exogenous plant growth regulators,indicating that physiological incompetence might be the major reason for the occurrence of the inferior grains.Rice panicles are composed of many branches with two types of extreme grains,the superior and the inferior.Traditionally,it has been well accepted that earlier flowers result in superior grains and late flowers generate inferior grains.However,these correlations have never been strictly examined in practice.In order to determine the accurate relationship between superior and inferior grains and the flowering order,we localized all the seeds in a panicle in four distinct rice species and systematically documented the rice flowering order,flower locations and the final grain weight for their relationships.Our results demonstrated that the grain weight is more heavily determined by the position of the seeds than by the flowering order.Despite earlier flowering has a positive correlation with the grain weight in general,grains from flowers blooming on the second day after anthesis generally gained the highest weight.This suggests earlier flowers may not result in superior grains.Therefore,we concluded that superior and inferior grains,commonly determined by grain weight,are not fully correlated with the flowering order in rice.Following the order of the grain weight,the superior grains are generally localized at the middle parts of the primary branches,whereas inferior grains were mainly on the last two secondary branches of the lower half part of the panicle.In addition,the weight of inferior grains were affected by spikelet thinning and spraying with exogenous plant growth regulators,indicating that physiological incompetence might be the major reason for the occurrence of the inferior grains.

关 键 词：flowering grains panicle inferior branches physiological flowers exogenous filling thinning 

分 类 号：S511[农业科学—作物学] S512.1