楸树叶片营养生物学及基因型间的遗传变异

以楸树27个无性系为材料,采用凯氏常量定氮法、钼蓝比色法、火焰光度法和原子吸收分光光度计法分别测定了叶片营养元素N、P、K、Ca、Mg的含量,并对叶片N、P、K、Ca、Mg含量的遗传变异规律及其与生长之间的相关性进行了分析。结果表明,不同无性系N素含量随着生长季节而降低。27个楸树无性系叶片中,除全N、全K、Mg含量在无性系间有显著的差异外,P、Ca含量在无性系间差异不显著。无性系的生长与N素含量有显著相关性,N素的多少直接影响楸树幼树的生长,但是楸树对于N素的吸收利用又受P、Ca的影响,P有利于N吸收、而对Ca有一定的制约作用;Mg对于K的吸收有一定的抑制作用,对于P的吸收有一定的促进作用。在测定的5种营养元素中,楸树所需营养元素N、P、K、Ca、Mg含量分别为16.800、0.079、5.740、2.700、0.317 g/kg。

Genetic variation and leaf nutritional biology of Catalpa bungei

The concentrations of nutrient(N,P,K,Ca and Mg) of leaves of 27 clones of Catalpa bungei C.A.Meyer leaves were determined by Kjeldahl method,Molybdenum blue colorimetric method and Flame photometry,respectively.Also the correlations between genetic variation of the composition content of N,P,K,Ca and Mg and the growth time of the plants were analyzed.The result suggested that N element content decrease as the plants grow among all the clones.Significant differences were found in the N,K,Mg content among 27 clones while no significant differences were found in P and Ca content among all the clones.Significant correlation was found between the growth of the clones and the content of N element.However,the absorption and utilization of the N element was influenced by the content of P and Ca,P element is conducive to the absorption of nitrogen while the effect of the Ca opposite;in addition,the Mg element could inhibit the absorption of the K element,and promote the P element absorption.The order of C.bungei nutrient requirements of the 5 nutrient elements was: N(16.800 g/kg),P(0.079 g/kg),K(5.740 g/kg),Ca(2.700 g/kg),Mg(0.317 g/kg),respectively.