Selection Of Rice Varieties And Construction Of Evaluation Index System For Rice Crab Symbiosis Model

Rice crab symbiosis model is an efficient three-dimensional planting and breeding ecological agriculture model.However,at present,the rice crab symbiosis model lacks suitable rice varieties,and the characteristics of rice varieties suitable for rice crab symbiosis model are not clear.This study was carried out in Datong Lake District,Yiyang City,Hunan Province from May to November 2021.Using random block design,the growth period,yield and yield composition,rice quality,growth and development characteristics,insect resistance and lodging resistance of various rice varieties were systematically evaluated under the rice crab symbiosis model,and the key evaluation indexes suitable for the selection of rice crab symbiosis model varieties were screened.The main results are as follows:(1)There were significant differences in yield among the tested rice varieties.Yongyou9 has the highest yield,up to 7.60t/hm~2;The yield of Yuxiangyou 261,Jingliangyou 1468and Qingxiangyou 261 reached 6.90-7.20t/hm~2.The path analysis of the yield components of each variety showed that the contribution of the yield components to the yield under the rice crab symbiosis model was as follows:grains per panicle>total spikelets>1000 grain weight>seed setting rate>effective panicles.(2)The difference of growth period among rice varieties reached 31 days.The growth period of 10 varieties such as Yongyou 9,Jingliangyou 1468 and Meixiangzhan 2 is130-149d,which can mature after river crab fishing,and is suitable for planting in rice crab symbiosis mode.The growth period of 9 varieties such as Meixiangzhan 2,Qingxiangyou261 and Huazheyou 261 is short,which does not meet the requirements of rice crab model production.(3)In terms of rice quality,the rice quality of six varieties including jingliangyou 1468,Jingliangyou 1212 and Huazheyou 261 reached the secondary standard issued by the Ministry.Among them,the varieties with higher yield level of Jingliangyou 1468 and Huazheyou 261 had better rice quality and were high-yield and high-quality varieties.(4)Cluster analysis of the tested rice varieties based on yield traits showed that the high-yield rice varieties under the rice crab symbiosis mode had the characteristics of high apparent conversion rate of dry matter,low lodging index,high bending resistance per plant and low attenuation rate of SPAD value after heading.These characteristics could be used as the key evaluation index for the screening of rice crab symbiotic rice varieties.In conclusion,Yongyou 9 and Jingliangyou 1468 were selected as rice varieties suitable for rice crab symbiosis model;At the same time,a rice variety evaluation index system of rice crab symbiosis model based on growth period,lodging resistance,apparent dry matter conversion rate and Leaf SPAD value was established.