Resistance Identification Of Different Rice Varieties To Brown Planthopper In Jiangxi Province

Rice is the main food crop in China,and the brown planthopper is one of the main pests in rice.It is one of the most economical and effective methods to control brown planthopper by planting insect-resistant rice varieties.It is of great significance for the control of the brown planthopper and the cultivation of insect-resistant varieties in Jiangxi Province to evaluate the resistance of rice varieties to the brown planthoppers and investigate occurrence of rice planthopper in the field.This paper evaluated the resistance of 72 rice varieties at seedling stage and adult stage promoting in Jiangxi Province,and identified the resistance of 25 rice varieties in 2017 for two years.The resistant rice varieties were identified and studied in the aspects of antibiosis,non-preference and tolerance.The occurrence of rice planthopper in field was investigated on 9 middle-rice varieties and 8 late rice varieties planting in Jiangxi Province.The main results are as follows: 1 Dynamics of rice planthopper occurrence in fields of different middle and late rice varietiesAiming at sustainable controlling of rice planthoppers,the field occurrence of rice planthoppers of 9 middle rice varieties and 8 late rice varieties in Jiangxi Province was investigated.The result were as follows.Brown planthoppers and white back planthoppers prefer to gather and feed on different rice varieties,and the occurrence of rice planthoppers in late rice varieties is severer than that in middle rice varieties.The nymphs of rice planthopper were the highest on Longliangyou1813,the adult of brown planthopper and white back planthopper were the highest,respectively,on the Huanghuazhan and Shenliangyou841.On late rice variety Longxiangyou130,the population of nymphs reached 3000 No.of rice planthoppers per 100 hills,and the adult density of brown planthopper and white back planthopper was the highest,followed by Fengyuanyouhuazhan.The population density of rice planthoppers in the whole growth stage of middle rice variety Quanyouhuazhan and Wushansimiao was relatively low,and the population density of rice planthoppers in the whole growth stage of late rice varieties was more than 2000 No.of rice planthoppers per 100 hills,except Jiyouyazhan,Tianyouyazhan,and that of Longxiangyou130 was more than 3723 No.of rice planthoppers per 100 hills.The results indicated that when the occurrence of rice planthopper on middle rice was relatively light,the frequency of drug control could be reduced.The number of rice planthopper on all late rice varieties was at a high level,especially when Longxiangyou130 and Fengyuan youhuazhan were planted,that drug control needed to be strengthened.2.Resistance level of 72 rice varieties at seedling stage and adult stageThe resistance of 72 rice varieties to BPH was evaluated using the Standard Seed-box Screening Technique(SSST)at seeding and adult stages of rice,which of 25 rice varieties was evaluated for two years.The results indicate that middle-rice variety Longliangyou534 was moderately resistant to BPH at the seeding stages for two years,while Wushansimiao at the seeding stages was sensitive to BPH in the second year.Late rice variety Gaoyouhong88 was moderately resistant to BPH at the adult stages,while Fengyuanyou2297 at the seeding stages was sensitive to BPH in the second year.In addition,the results of the two years for some varieties were different.Guangliangyou1822,Huanghuazhan,LongLiangyouhuazhan and Liangyou619 were sensitive or highly sensitive to BPH at the seeding stages,but they were moderately resistant to BPH at the adult stages.The remaining early rice varieties,middle-rice varieties and Late rice varieties were sensitive or highly sensitive to BPH at both of the seeding and adult stages.At present,most of the rice varieties widely grown in Jiangxi Province are susceptible and high-sensitivity varieties,lacking resistant varieties,and the resistance is not high.3.Resistance mechanism of resistant rice varietiesThe result showed that compared with TN1,Lonliangyou 534,which had resistance at seedling stage,extended the development time of nymph of brown planthopper and had no effect on other biological indexes of brown planthopper.The number of nymph of brown planthopper on Wushansimiao seedlings was significantly lower than that of Longliangyou534,and the plant functional loss index of both varieties was lower than TN1.Compared with TN1,the growth time of nymphs of brown planthopper was prolonged feeding on Gaoyouhong88 and Fengyuanyou2297 with resistance at the plant stage,and the number of brown planthopper nymph hatching was the least on Gaoyouhong88.There was no difference in nymph number of brown planthopper between the two varieties,and the plant functional loss index of both varieties was less than TN1.The effect of different rice varieties on brown planthopper was mainly reflected in the tolerance,but the non-preference and antibiosis of different rice varieties were not obvious.