Comparative Study of Grain Filling Characteristics in Maize

Abstract This study was conducted to illustrate the differences in grain filling characteristics between different maize materials in the Northern area of Huanghuaihai Plain, to provide a theoretical basis for the breeding of maize varieties with suitable maturation stage. The new maize hybrid Hengzao 8 was selected as an experimental material, and varieties Huamei 1 and Zhengdan 958 were selected as CK. The changes in grain size, water content, dry weight and grain filling characteristics during grain filling process were studied, and the yield components were analyzed. The grain sizes of the 3 maize materials increased rapidly within 20 d after pollination and reached their peak values on the 45^th d after pollination. Hengzao 8 had the biggest grains, while Zhengdan 958 showed the smallest grains. The 3 maize materials showed high growth speeds of dry matter from the 15^th to the 55^th d after pollination, Hengzao 8 being the fastest and Zhengdan 958 being the slowest. The growth speeds of grain dry matter dropped afterwards. The grain filling rates of the 3 materials fit the unimodal distribution; and Hengzao 8 presented the highest peak value, while Zhengdan 958 exhibited the lowest peak value. Grain size was positively correlated with water amount and negatively correlated with water content, and the grain filling rate was positively correlated with water amount. Regression analysis revealed that when the water contents of the 3 materials reached 57%, grain filling rates reached their peak values. The Logistic model showed that the maximum grain filling rate （Gmax） and the mean filling rate （Gmean） were higher in Hengzao 8 whose active grain filling stage, early stage （T1） , middle stage （T2） and late stage （T3） were shorter than other 2 varieties. The differences in 1 000-grain weight between the 3 materials were responsible for the differences in the yield. The grain filling characteristics of Hengzao 8 are decisive for achieving early maturation and high yield.

Morphological and physiological traits of large-panicle rice varieties with high filled-grain percentage

financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）