Yield Formation And Quality Characteristics Of High-quality Hybrid Rice Jingliangyou 1468

Rice is an important food crop in China.It is very important to maintain the stability of rice production to ensure food security in China.At the same time,with the rapid development of social economy in China,rice quality has been paid more and more attention by rice consumers.How to improve rice quality under the premise of ensuring rice yield has become a major challenge for rice production in China.In recent years,Chinese rice breeders have developed a number of hybrid rice varieties with good quality through unremitting efforts.However,the main reasons for the improvement of yield and quality of high-quality hybrid rice and the effect of sowing date on yield and quality of high-quality hybrid rice are not clear.In order to make clear the yield formation and quality characteristics of the high-quality hybrid rice Jingliangyou 1468 and provide a theoretical basis for the breeding and cultivation of high-quality hybrid rice.A field experiment was conducted at the experimental field of Hengyang Academy of Agricultural Sciences in Hengyang City,Hunan Province in 2019 and 2020.Four sowing dates were set and eight environments were formed in two years.Two hybrid rice varieties（Jingliangyou 1468,a high-quality hybrid rice approved and promoted by the state in 2017;and liangyoupeijiu was the first batch of super hybrid rice approved and promoted by the state in 1999）with 18years difference in approval time were used as materials in this study.The yield formation characteristics and quality characteristics of the two varieties were compared emphatically.The main results as follows:（1）Jingliangyou 1468 has high yield.The yield of Jingliangyou 1468 were 10.09 t hm^-2and 9.74 t hm^-2in 2019 and 2020,respectively,which was 15.2%and 8.1%higher than that of Liangyoupeijiu.The panicle number and spikelet filling of Jingliangyou 1468 were significantly higher than those of Liangyoupeijiu.In 2019,the panicle number and spikelet filling of Jingliangyou 1468 were 318×10⁴hm^-2and 86.6%,respectively,which were 16.9%and 23.0%higher than those of Liangyoupeijiu.In 2020,the panicle number and spikelet filling of Jingliangyou 1468 were 327×10⁴hm^-2and 72.9%,respectively,which were 19.8%and 18.5%higher than those of Liangyoupeijiu.At the same time,the dry matter production after heading of Jingliangyou 1468 was higher,which was 636 g m^-2and 473 g m^-2in 2019and 2020,respectively,68.3%and 10.3%higher than that of Liangyoupeijiu.（2）Jingliangyou 1468 has good rice quality.The head rice rate of Jingliangyou 1468was 12.6%and 15.6%higher than Liangyoupeijiu in 2019 and 2020,respectively;The percentage of chalky rice grains and degree of chalkiness of Jingliangyou 1468 were 79.0%and 79.3%,64.1%and 60.2%lower than Liangyoupeijiu,respectively;The alkali spreading value of Jingliangyou 1468 was 10.3%and 9.3%higher than Liangyoupeijiu,respectively,and the amylose content of Jingliangyou 1468 was 28.0%and 25.5%lower than Liangyoupeijiu,respectively.Jingliangyou 1468 had higher head milled rice rate,lower percentage of chalky rice grains and degree of chalkiness,higher alkali spreading value and lower amylose content,which made its processing,appearance and cooking and eating quality better than Liangyoupeijiu.The peak viscosity and breakdown value of RVA profile characteristics of Jingliangyou 1468 were significantly higher than those of Liangyoupeijiu,and the setback value was significantly lower than that of Liangyoupeijiu,which further proved that its taste quality was better.The hardness,adhesiveness,cohesiveness,adhesion,elasticity,chewiness and resilience of Jingliangyou 1468 rice were significantly lower than those of Liangyoupeijiu rice,and its rice texture was softer.