关键词: 早中熟水稻, 播期, 产量, 品质, 农艺性状, 主成分分析, GGE模型分析

Abstract: The effect of sowing dates［May 5（T1），May 11（T2），May 17（T3），May 23（T4），May 29（T5），June 4（T6），June 10（T7），June 16（T8），June 22（T9）and June 28（T10）］on yield and quality of different maturity types of rice was studied with four portions each for early and middle rice as experimental materials. Principal components of yield and quality related characters of early and middle rice under different sowing dates were analyzed，and a comprehensive evaluation of the stability of experimental materials and sowing dates was conducted using GGE biplot based on yield and chalkiness，so as to provide theoretical basis for the selection of suitable rice types and sowing dates in rice field planting in Huang⁃Huai⁃Hai region. The results showed that sowing date had a significant impact on both rice yield and quality. The duration from sowing to heading for early and middle rice generally decreased with the delay of sowing date. The changes of growth period varied depending on the experimental materials. Under T1 treatment，early and middle rice had the longest growth period，and middle rice had
the shortest growth period under T6 treatment. The length and diameter of stem，as well as the length of sword leaf，varied greatly in early rice，while the number of panicles per plant，seed setting rate and thousand⁃grain weight varied greatly in middle rice. The overall yield of early and middle rice showed a trend of first increase，then decrease and then increase with the delay of sowing date. Among them，early rice A1（TH2），A2（Huaxiangjing 2）and A4（Jindao 272）had the highest yields under T4 treatment，which were 5 902.09 kg/ha，5 569.03 kg/ha and 8 916.24 kg/ha，respectively；early rice A3（Jindao 572）had the highest yield of 10 194.01 kg/ha under T3 treatment；the lowest yields were obtained under T6 treatment. The yields of middle rice Linxiu 6812，Xu 60233，Lindao 10 and Nanjing 9308 were the highest under T4 treatment，which were 9 352.54 kg/ha，9 515.23 kg/ha，9 179.88 kg/ha and 7 925.09 kg/ha，respectively；the yields were the lowest under T1 treatment. The crude protein content in grain of early and middle rice showed an overall trend of first increase，then decrease and then increase with the delay of sowing date. The amylose content in grain of early and middle rice showed an overall trend of first decrease and then increase with the delay of sowing date. The chalkiness degree of grain of early rice generally decreased with the delay of sowing date，while for middle rice，it showed an overall trend of first decrease and then increase with the delay of sowing date. The results of principal component analysis indicated that T1，T2，and T3 could effectively distinguish different maturity types of rice materials，that was，the traits of different maturity types of rice materials could be fully expressed under these sowing dates.The analysis results of the GEE model indicated that the comprehensive scores of materials A3 and A4，sowing dates T3 and T2 were relatively higher.

Key words: Early and middle rice, Sowing date, Yield, Quality, Agronomic characters, Principal component analysis, GGE model analysis