Characteristics of Stem Growth and Formation of Grain of indica Hybrid Rice in Different Planting Methods and Their Correlation with Meteorological Factors
TIAN Qing-lan;LIU Bo;SUN Hong;HE Sha;ZHONG Xiao-yuan;ZHAO Min;REN Wan-jun;College of Agronomy,Sichuan Agricultural University / Key Laboratory of Crop Physiology,Ecology,and Cultivation in Southwest China /Institute of Ecological Agriculture,Sichuan Agricultural University;Pixian Meteorological Bureau;
The objective of this study is to explore the growth pattern and differences of stem and panicle of indica hybrid rice under various planting methods in panicle differentiation stage,and to investigate the effects of planting methods on grain formation.A split plot experiment was carried out in 2014 with two factors,including variety(Yixiangyou 2115 and F you 498)and planting method(mechanized direct-seeding,MD;mechanized transplanting,MT;hand transplanting,HT).The Growth pattern of stem and panicle,the formation characteristics of grain were researched,and the relationship between meteorological factors in panicle differentiation stage and the growth of stem and panicle were analyzed.The results were as follows:1)Length of first to third elongated internodes from the base stablized 20 d,16dand 12 dbefore heading,respectively,indicating that reducing length and increasing roughness of basal first and second internodes should be done 16 dbefore heading.Dry panicle weight and ratio of panicle to stem increased rapidly 12 dbefore heading.2)Dry weight ratio of panicle to stem was significantly positively correlated with rachis branches and spiketets from 16 dbefore heading to heading date.The ability that panicle competing assimilates with stem directly affected the formation of grain.3)MT had higher dry weight ratio of panicle to stem in middle and late differentiation stage of panicle,MT also had higher dry matter accumulation of panicle than MD and HT in heading stage.So MT had an advantage in the number of grains.MT also had higher crop growth rate of population and higher dry matter accumulation per stem and population than MD and HT after jointing.MT also had higher leaf area index in heading,and its grain leaf ratio was higher than MD,so MT contributed to more grains and spikelets,longer panicle length.F you 498 with large panicle had higher dry matter weight of panicle in heading than Yixiangyou 2115 with middle panicle,and it had higher dry matter weight ratio of panicle to stem than Yixiangyou 2115,these were the important reason for that F you 498 had higher number of grains.Denser grain of F you 498 compared to Yixiangyou2115 resulted from its larger leaf area index and grain to leaf ratio.4)MT had the longest growth duration,while MD had the shortest.MT had a longer panicle differentiation stage,higher accumulated temperature and illumination hours,providing agood temperature and light condition for the formation of grain in MT.Length and dry weight of stem and length of panicle were greatly influenced by meteorological factors.Suitable temperature and a certain amount of accumulated temperature before booting was conducive to the elongation of stem and panicle and filling of stem.Given the differences in growth under different planting methods and of varieties,we should take measures to regulate growth of stem and panicle and the distribution of assimilates in an appropriate time.In order to achieve the goal of increasing grain yield,the dry weight ratio of panicle to stem should be increased on the basis of cultivating strong stalk.
【Fund】： 国家粮食丰产科技工程资助项目(2013BAD07B13-02 2011BAD16B05);; 国家公益性行业(农业)科研专项(201303102)
【CateGory Index】： S511.21
【CateGory Index】： S511.21