Analysis on Factors Affecting Seedling Establishment in Rice

Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production.Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl(long,medium and short)were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions.The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations,and two semi-dwarf varieties(G140,Zhong 96-21)with good seedling establishments and optimum mesocotyl lengths were found.The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl,coleoptile,seeding depth,flooding duration,and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl,coleoptile,mesocotyl×coleoptile, seeding depth,flooding duration and mesocotyl×sowing depth in the experiment for seedling establishment.