种源与同质园环境对刨花楠幼苗叶功能性状的影响

Effects of provenance and common garden environment on leaf functional traits of Machilus pauhoi seedlings

为了解刨花楠(Machilus pauhoi)叶片在生长过程中对资源的分配利用及对环境变化的响应特征,探究刨花楠叶功能性状变异的主要影响机制,以江西南昌与福建顺昌两地同质园的1.5年生刨花楠苗木为研究对象,分析种源与同质园环境对其叶面积(LA)、叶干重(LDW)、比叶重(LMA)、叶形态指数(LMI)以及叶组织密度(LTD)等主要叶功能性状变化的影响.结果显示,刨花楠苗木的LA、LDW、LMA、LMI及LTD等叶功能性状指标受种源及同质园土壤环境的共同影响,且同质园土壤环境对苗木叶功能性状影响的贡献高于种源(LA性状除外);种源地气温是影响刨花楠种源间苗木叶功能性状变异的主要因素,其中LA主要受种源地7月气温影响(P <0.01),LDW和LMI主要受种源地年均温影响(P <0.01),LMA和LTD则分别受种源地纬度和1月气温影响(P <0.01);土壤养分是影响同质园间苗木叶功能性状差异的主要因素,除LA性状在两同质园间无明显差异外,3个种源苗木的叶功能性状指标值均以江西南昌同质园为大;苗木LA主要受种源地环境或遗传基因影响,LDW、LMA、LMI及LTD等叶功能性状指标则主要受同质园土壤养分高低影响;苗木LA、LDW、LMA、LMI及LTD等叶功能性状指标的表型可塑性指数以LTD最大(0.96),LA最小(0.53).本研究表明刨花楠苗木不同叶功能性状对种源和同质园环境的响应并不一致;结果可为刨花楠优良种源选择、苗木高效培育等提供指导.

To understand the resource allocation and utilization of Machilus pauhoi leaves and their response to environmental changes during the growth, and to further explore the main mechanism for the variation in functional traits of M. pauhoi,1.5-year-old M. pauhoi seedlings were studied. We compared the differences in leaf area(LA), leaf dry weight(LDW), leaf mass per area(LMA), leaf morphology index(LMI), and leaf tissue density(LTD) between two common gardens in Nanchang,Jiangxi Province and Shunchang, Fujian Province. We analyzed the effects of provenance and common garden environments on the functional traits of M. pauhoi leaves. The results showed that provenance and the soil environment of the common garden jointly affected the leaf functional traits, such as LA, LDW, LMA, LMI, and LTD of M. pauhoi seedlings, and the contribution of the soil environment of the common garden on the functional traits of seedlings was higher than that of the provenance(except for LA). The temperature of provenance was the main factor affecting the variation of functional traits of M. pauhoi seedlings among different provenances. LA was mainly affected by the provenance temperature in July(P< 0.01), and LDW and LMI were mainly affected by the annual average temperature of the provenance(P< 0.01). LMA and LTD were affected by the latitude and the provenance temperature in January(P <0.01). Soil fertility and nutrients were the main factors affecting the differences in functional traits between the two common gardens, except that there was no significant difference in LA. The leaf functional traits of seedlings in the Nanchang common garden were the largest among three provenances. LA was mainly affected by the provenance environment or genetics. Leaf functional traits such, as LDW, LMA, LMI, and LTD were mainly affected by soil fertility and nutrients in common gardens. The phenotypic plasticity index of leaf functional traits was the largest in LTD(0.96) and the smallest in LA(0.53), indicating that the leaf functional traits of seedlings responded differently to the provenance and common garden environment. The results could provide guidance for excellent provenance selection and efficient breeding of M. pauhoi seedlings.