Study On The Difference Of Yield And Lodging Of Rapeseed In The Yangtze River Basin

In the rapeseed production,the characteristics of the varieties with excellent yield and lodging resistance have important reference significance for the selection of new varieties in the later period.This experiment took a regional test method from2015 to 2017 and 20 varieties were selected and planted in the Yangtze River Basin?Wuhan,Huanggang,Wuxue,Nanchang,Kunming,Chengdu,Nanjing?ecological areas.Screened different types of cultivars and studied key agronomic traits related to cultivars.Explored the relationship between meteorological factors?sunshine hours,temperature,effective accumulated temperature,solar radiation,rainfall and so on?with yield and lodging.1.Among agronomic indexes,varieties of high-yield with strong adaptability and low-yield with weak adaptability were mainly affected by the above-ground biomass and the number of siliques per plant.The factors that limited the yield increase of the low-yield with weak adaptability varieties were also had crown diameter and branch number.Therefore,when select a high-yield product,priority will be given to increasing the number of siliques per plant and above-ground biomass,and on the basis of ensuring the number of siliques per plant and above-ground biomass,increasing root crown diameter and branch number.Among the physiological indicators of stems,the low-yield with weak adaptability were affected by the content of cellulose and lignin in the stems.High-yield with strong adaptability had no obvious correlation with cellulose and lignin.When the cellulose content of rapeseed stalk were large,and the lignin content were less,it would help increased the yield of low-yield with weak adaptability varieties.The low-yield with weak adaptability varieties were vulnerabled to environmental factors.The key meteorological factors affected the above-ground biomass were solar radiation,rainfall,and daily temperature difference.Among them,rainfall was a key indicator of above-ground biomass?Y=55.5187+1.4873X₁-1.6843X₃-3.1133X₄ R²=0.7403,Among them,Y,X₁,X₃,and X₄ represent above-ground biomass,seedling stage,flowering stage,and pod stage rainfall?.There were more rainfall at seedling stage and less rainfall during flowering and pod stage,which would beneficial to increased above-ground biomass.The key meteorological factors affected the number of siliques per plant were solar radiation,sunshine hours,and average temperature.The sunshine hours was the main indexaffectedthenumberofsiliquesperplant?Y=-107.4756-41.0334X₁+51.4413X₄+57.3412X₅ R²=0.7974,Among them,Y,X₁,X₄,and X₅ represent the number of pods per plant,seedling stage,pod stage,and whole growth period sunshine hours?.The number of sunshine hours at the seedling stage was relatively small,and the number of sunshine hours during the pod stage and the whole growth peridis were relatively high,which would conducived to increase the yield of rapeseed.2.The strong adaptability with high resistance and the weak adaptability with low resistance were all related to breaking resistance.Factors limited the increase in lodging resistance of the weak adaptability with low resistance varieties included branch height and plant height.Therefore,when breeding high-resistance cultivars,priority would be given to enhance the stalk's breaking resistance,and on the basis of ensuring the greater breaking resistance of the plant,the branch height and plant height would be reduced.Among the physiological indicators of stems,both the strong adaptability with high resistance and the weak adaptability with low resistance were affected by the cellulose content in the stems.Lodging index of the weak adaptability with low resistance was affected by lignin content in stems at the same time.Therefore,to increase the lodging resistance of weak adaptability with low resistance cultivars can increase the cellulose content of plant stalks first,and then consider the increase of lignin content.Lodging traits of weak adaptability with low resistance varieties were susceptibled to environmental factors.The impact of branching high-key meteorological factors were daily average temperature difference,solar radiation,sunshine hours.The most important influence factor was the daily temperature difference?Y=192.0558-5.2729X₂-7.8765X₃ R²=0.8271,Among them,Y,X₂,and X₃ represent branch height,bolting stage,and the flowering period daily temperature difference,respectively?.The larger daily temperature difference during bolting stage and flowering will increase plant lodging resistance.The plant height of the weak adaptability with low resistance varieties was mainly affected by solar radiation,sunshine hours,and rainfall.The most important influence factor was rainfall?Y=130.0967+8.3776X₁+15.4994X₂+9.8460X₅ R²=0.8616,Y,X₁,X₂,and X₅represent plant height,seedling stage,bolting stage,and whole growth period rainfall,respectively?.Rainfall during the seedling stage,bolting stage and whole growth perid should not be excessive.3.The most critical index affecting yield was the number of siliques per plant and the most critical indicator of lodging was breaking resistance.Therefore,the number of siliques per plant with 177.8-209.2 which can be used as an indicator for the selection of high-yield and ecologically-adapted varieties in the Yangtze River Basin.The breaking resistance 99.1 N-121.8 N can be selected as the high-resistance and ecologically-adapted varieties in the Yangtze River Basin.At the same time,breaking resistance and cellulose were the comprehensive indicators for the coordination of yield and lodging resistance.The greater of the fracture resistance,the more cellulose content of the stalk,the higher of the yield and the stronger of the lodging resistance.Appropriate breaking resistance index range is 99.1 N-121.8 N,cellulose range is 24.67%-30.11%...