论文部分内容阅读
【目的】筛选耐低磷苜蓿品种及与耐低磷密切相关的性状指标,进一步为紫花苜蓿耐低磷机制研究和生产应用提供理论依据。【方法】在溶液培养条件下,对20个紫花苜蓿品种的24 d龄的幼苗分别进行常磷(500μmol·L~(-1) KH2PO4)和低磷(5μmol·L~(-1) KH_2PO_4)处理,30 d后检测各品种的茎叶干重(SLW)、株高(PH)、根干重(RW)、根冠比(RS)、总根长(TRL)、根表面积(RSA)、全磷含量(TP)、磷利用率(PUE)、酸性磷酸酶活性(ACPA),并计算各指标的耐低磷系数。进一步对各指标的耐低磷系数进行相关性分析,并运用主成分分析、隶属函数分析、回归分析及聚类分析方法,综合评价不同品种耐低磷性及筛选与耐低磷密切相关的指标,同时建立耐低磷评价模型。【结果】低磷胁迫下,各品种紫花苜蓿的地上部分生长受到抑制,地下根系增大,全磷含量显著下降(P<0.01)。通过主成分分析可将9个单项指标转化为4个新的相互独立的综合指标。进一步利用隶属函数对4个新的综合指标进行耐低磷综合评价,结合聚类分析结果,可将20个紫花苜蓿品种可分为三类,其中耐低磷较强的品种包括敖汉、新牧1号、耐盐之星、皇冠;中度耐低磷品种包括骑士T、驯鹿、牧歌37CR、龙牧801等9个品种;耐低磷较弱的品种包括巨能Ⅱ、中苜2号、康赛等7个品种。进一步利用逐步回归分析方法建立了紫花苜蓿耐低磷性评价数学模型D=-0.7997+0.3856SLW+0.2025PH+0.3789RW+0.1051TRL+0.4188TP+0.1347ACPA,方程的决定系数R~2=0.9982.【结论】通过分析紫花苜蓿不同品种的耐低磷能力,得出耐低磷较强的品种为敖汉、新牧1号、耐盐之星、皇冠,与耐低磷性最相关的指标有茎叶干重、株高、根干重、总根长、全磷含量和酸性磷酸酶活性,可用于紫花苜蓿耐低磷性的评价筛选。
【Objective】 The objective of this study was to screen the characters of low-phosphorus-tolerant alfalfa cultivars and closely related to low-phosphorus tolerance, and to provide a theoretical basis for the research on low-phosphorus tolerance mechanism and production and application of alfalfa. 【Method】 The twenty-four-day-old seedlings of 20 alfalfa cultivars were treated with 500μmol·L -1 KH2PO4 and 5μmol·L -1 KH_2PO_4, respectively, under solution culture conditions. After 30 days, the dry matter weight (SLW), plant height (PH), root dry weight (RW), root / shoot ratio (RS), total root length (TRL), root surface area Total phosphorus (TP), PUE and ACPA were calculated, and the low phosphorus tolerance index of each index was calculated. Furthermore, the correlation analysis was carried out on the low phosphorus tolerance index of each index. Principal component analysis, membership function analysis, regression analysis and cluster analysis were used to evaluate the indexes of low phosphorus tolerance and low phosphorus tolerance , At the same time to establish low phosphorus tolerance evaluation model. 【Result】 Under low-phosphorus stress, the growth of above-ground parts of alfalfa was inhibited, the underground roots increased, and the content of total phosphorus decreased significantly (P <0.01). Through the principal component analysis, 9 individual indicators can be transformed into 4 new mutually independent comprehensive indicators. Further use of membership functions to evaluate the four new comprehensive indicators of low phosphorus tolerance, combined with the results of cluster analysis, 20 alfalfa varieties can be divided into three categories, including low-phosphorus-resistant varieties include Aohan, new Grazing salt, crown; moderate resistance to low phosphorus varieties, including Knight T, reindeer, pastoral 37CR, Longmu 801 and other 9 varieties; weaker varieties of low phosphorus tolerance, including giant can Ⅱ, in the alfalfa 2 , Kangsi and other seven varieties. Further use of stepwise regression analysis established mathematical model of alfalfa low phosphorus tolerance evaluation D = -0.7997 + 0.3856SLW + 0.2025PH + 0.3789RW + 0.1051TRL + 0.4188TP + 0.1347ACPA, the coefficient of determination of the equation R ~ 2 = 0.9982. 【Conclusion】 By analyzing the ability of low-phosphorus tolerance of different varieties of alfalfa, it was concluded that Aohan, Xinmu 1, salt-tolerant star and crown were the most resistant to low phosphorus. Stem and leaf dry weight, plant height, root dry weight, total root length, total phosphorus content and acid phosphatase activity, can be used for alfalfa low phosphorus tolerance evaluation screening.