Effect Of Phosphorus Fertilization On The Growth And Development Of Adzuki Bean

Phosphorus is one of the essential elements for plant growth. Soilphosphorus deficiency affects normal growth and production of crops.Choosing Phosphorus efficiency genotype is an economical,environmentally friendly and easy-to-operate method to improve theutilization efficiency of Phosphorus. Being of great nutritive value,adzuki bean is an important crop planted in poor soil (barren oil,salinization of soil, drought, etc.) of northern China. Shanxi province, isone of the major bean-producing regions. In this paper, with adzukibeans as the test materials, agronomic traits and physiologicalcharacteristics of12kinds of adzuki beans both in the conditions ofnormal phosphorus and deficiency phosphorus are studied withhydroponics imitation of Phosphorus deficiency. Under laboratoryconditions, so as to choose the indicators for identification of beans’tolerance to phosphorus and the varieties of adzuki beans that is ofstrong tolerance to phosphorus in seedling period. Agronomic traits andphysiological characteristics of3kinds of adzuki beans that are ofdifferent phosphorus efficiency under different levels of phosphorus arestudied with pot experiment, so as to explore the relevance betweenplant morphology of adzuki beans and accumulation of phosphorus, andto make sure the differences in physiological characteristics andaccumulation of phosphorus on different adzuki beans. Thus, it can provide scientific basis for improving utilization efficiency of Phosphorusin soil and perfect the breeding and cultivation of adzuki beans. Resultsare as follows:Hydroponic experiment results show that:(1)Phosphorus deficiency treatment significantly reduced the plantheight, stem diameter and leaf area of12adzuki bean varieties, andwhile increased the root length and shoot ratio. But the degree ofvariability varies according to the kinds of adzuki beans.The changedegree is difference in12adzuki bean varities. The leaf area of Jinhong5seedling decreased the most compared with those in normalPhosphorus supply level, reducing70.88%. The leaf area of Jingnong2seedling decreased the smallest, reducing19.72%. And the dry weightof root reduced with an average of46.67%, while the root length androot-shoot ratio reduced with an average of36.43%and56.00%respectively.(2)Under phosphorus deficiency treatment, the chlorophyll content, Fmand Fv/Fm of all varities adzuki bean had a declined of different degrees.And the MDA content, SOD activity, POD activity, root vigour, apase andFo were increased compared with these on normal phosphorus supplylevel. The phosphorus content in roots, stems and leaves decreasedunder phosphorus deficiency condition. But phosphorus contents inroots, stems and leaves were different, while the phosphorus content ofleaves was highest and the average value decreased the most.(3)The phosphorus deficiency treatment had adverse effect on theagronomic traits in seedling periods. Leaf area and root shoot ratio weregreatly influenced by deficiency phosphorus, which was suitable as theselecting indicator to evaluate the tolerance deficiency phosphorus ability of adzuki bean. From synthetical indices of tolerance deficiencyphosphorus, the ability of tolerance phosphorus deficiency were listedhere by decreased order: B1789>Jin hong1>Jing nong2>Jing nong86-5>bao876-16>B1783>Jing nong8>bai hong4>bao hong8824-17>Dong beida hong pao>Bai hong6>Jin hong5, As was shown, there were smallerchanges of physiological indicators in the stronger varities of tolerancedeficiency phosphorus ability,while there were biggest changes ofphysiological indicators in the weaker varities of tolerance deficiencyphosphorus ability.Pot experiment results show that:(1)With the increase of phosphorus rate, the leaf area of Jinhongincreased, while plant height increased first and then decreased, whilethe leaf area and plant height of other two cultivars are increased firstand declined later. The changes of adzuki bean root shoot ratio,increase of the total root length and root area which affected theamount of substance both of overground part and total root dry.(2)With increase of the phosphorus rate, root vigour of three varitiesadzuki bean seedling increased first and then decreased, and rootphosphatase showed a downward trend, while the accumulation ofphosphorus showed an increasing trend. With the increase ofphosphorus rate, the activities of SOD and POD present a trend thatincrease first and then decrease. The relative conductivity and MDAcontent are higher under the levels of lower and higher both in high andlow levels of phosphorus. The SOD and POD activity in Jinhong1seedling are lower, and the MDA content is higher than those in theother two cultivas. Under the levels of low and high phosphorus, thechlorophyll relative contents are low, but the difference is not significant, the maximum fluorescence (Fm) and the maximal photochemical efficiency (Fv/Fm) are increased, and Fo is decreased first andthen increased.(3)As were reflected from plant morphology, physiology and otherindicators, there were significant differences among three cultivarsadzuki beans under phosphorus stress.By increasing root length,rootarea and root shoot ratio of three varieties of adzuki bean seedling wasled to a significant increased, which significantly altered the distributionof dry matter between underground and aboveground.Through hydroponic phosphorus deficiency experiment of12cultivarsadzuki bean seedling, three species of adzuki beans with differentphosphorus sensitivity were screened.These three varieties wereneeded to futher study by setting different phosphorus rate in potexperiment. The results showed that: the ability of tolerance to low andhigh phosphours stress is stronger in cultivar Jinhong1than in the othertwos.And the phosphorus content reached100mg/kg, which is verysuitable for the growth of adzuki bean seedling.