Identification Of Aluminum Tolerance Of Different Pea Varieties And Study On The Mechanism Of Aluminum Tolerance

Aluminum is one of the most abundant metal elements in the earth’s crust,which accounts for about 8%of the total metal in the crust.Generally,aluminum in soil exists in the form of silicate and has no effect on crop planting,but in acidic soil,aluminum exists as soluble ion in soil,which is harmful to crop growth.Pea is the fourth largest soybean crop in the world,and China is the second largest producer of pea after Canada.Pea planting is closely related to soil acidification,acid soil will limit the growth of pea,mainly because of aluminum toxicity in the soil.In recent years,the situation of pea cultivation in the south of China has been very poor.Well,the root cause is the serious consequences of a large area of soil acidification.How to solve the problem of aluminum toxicity to peas in acidic soil can not only be improved by lime,but also can be solved more economically and effectively by screening the varieties of aluminum-tolerant pea.In acidic soil,aluminum toxicity varies with different crops or different varieties of the same crop.In this study,17unscreened pea varieties were treated with 0μmol·L^-1and 30μmol·L^-1Al Cl₃solution.The root length and root elongation of different pea varieties under aluminum treatment were analyzed.The relative root growth rate and aluminum content in the lateral root tip of pea were used to identify the aluminum tolerance of pea varieties.The varieties with obvious differences in aluminum tolerance were screened out,and the mechanism of aluminum tolerance was preliminarily explored.The experiment was divided into two stages.In the first stage,the aluminum tolerance of 17 pea varieties was screened and identified,treated with Al Cl₃solution of 0μmol·L^-1and30μmol·L^-1,respectively,and the relative root growth rate of pea was counted under different treatments.Aluminum toxicity accumulated in the main root tip of pea and aluminum content in the lateral root tip of pea in order to screen aluminum-resistant and aluminum-sensitive pea varieties.The second stage of the test,the first stage of the test.Results on the basis of the results,two varieties of pea with relatively higher aluminum tolerance and more aluminum sensitivity were selected,and the relative subjects of aluminum tolerance mechanism of pea were compared and the following conclusions were drawn:Root elongation,root relative elongation,hematoxylin staining and Morin staining of 17 pea cultivars were analyzed under 30μmol·L^-1Al Cl₃.The results showed that root elongation was inhibited in different varieties under aluminum stress.The results were as follows:PS-101,PS-9,PS-13,PS-102,PS-96 and PS-109 varieties had higher root elongation,The relative root elongation of PS-11、PS-97、PS-88 and PS-110 was lower;and the fluorescence intensity of PS-15,PS-33 and PS-98 was relatively weak in Morin staining,while the fluorescence intensity of other 14varieties was relatively large,and the accumulation of aluminum was obviously different.The results of hematoxylin staining showed that,PS-88,PS-110,PS-11,PS-97,PS-102,George,PS-98 had a wider and deeper staining area at the root tip of lateral root,and some of them were purple-brown or even dark-brown,indicating that it was a black-brown or even dark-brown color.After treatment with 30μmol·L^-1Al Cl₃solution for 24 hours,the lateral root tip was seriously affected by aluminum toxicity.The sample roots of the remaining 10 pea varieties were slightly stained.It can be seen from the picture that there are three varieties of PS-15,PS-7,PS-19 with low dyeing degree,among which PS-15,PS-7 varieties have no obvious aluminum toxicity.Based on the above results,we conclude that the PS-7,PS-15,PS-19 variety is an aluminum-tolerant pea variety,Cam.Eor,PS-97 is an aluminum sensitive variety.The mechanism of aluminum tolerance difference of pea cultivars was studied in this paper.It was found that under aluminum stress,the degree of alkalinity of PS-15was the highest,so it was speculated that PS-15 was Al-tolerant pea,while PS-97 was the lowest,and PS-97 was Al-sensitive.The results of p H,analysis by bromcresol green indicator in pea rhizosphere under aluminum stress showed that aluminum inhibited the transportation of auxin,increased the lateral rhizosphere p H,of pea,and then caused toxicity to pea,which further confirmed that Litter snap was Al-tolerant.PS-97 is aluminum sensitive.And by comparing these four varieties,The fluorescence intensity of PA treated with aluminum also confirmed that Litter snap and PS-97 were Al-sensitive and Aston and PS-9 were Al-tolerant.