穗粒数和粒重是玉米单穗产量的组成因子。本项目针对穗粒数和粒重两个复杂的产量相关性状，结合全基因组关联分析和连锁分析，初步阐明控制玉米穗粒数和粒重遗传位点数目、主效位点及其效应。针对KRN4、ZmEL3、UB3三个穗粒数主效位点，解析基因功能和调控途径。针对mn8, O11, O2, PBF四个粒重相关基因，解析基因功能和调控途径。分别在W22和Ye478背景下，探索KRN4、ZmEL3、UB3三个基因调控玉米穗粒数的遗传互作网络，以及mn8, O11, O2, PBF四个基因调控玉米粒重的遗传互作网络。项目研究结果将为玉米穗粒数和粒重的遗传改良提供理论依据和基因资源。

Kernel number (KN) and kernel weight (KW) are two important components of grain yield per ear of maize, and are also two complex quantitative traits. In the project, we'll elucidate number of loci for the KN and KW and effects of major loci using genome-wide association study and linkage analysis, to dissect the genetic architecture of KN and KW in maize. Furthermore, we'll analyze the biological functions and acting mechanisms of three kernel number-associated loci, KRN4, ZmEL3 and UB3, and establish genetic networks of the three genes in the regulation of kernel number at W22 and Ye478 genetic background. Moreover, we'll analyze the biological functions and acting mechanisms of four kernel weight-associated loci, mn8, O11, O2 and PBF, and establish genetic networks of the four genes in the regulation of kernel weight at W22 and Ye478 genetic background. The outcomes produced from the project will expand our understanding on the genetic architecture of KN and KW, and provide the available genes for genetic improvement of KN and KW in maize.