不同种群高山松1年生播种苗木生长节律及其变异

Annual Seedling Growth Dynamic Rhythm and Variation of One-Year Pinus densata among Populations

对高山松(Pinus densata)天然分布区内的8个种群苗高与地径生长量定株、定期观测,采用Logistic方程对其生长过程进行拟合,分析了高山松不同种群在理论亲本种云南松生境下1年生苗木生长节律及其变异。结果表明:①)发芽期结束后,苗高、地径生长呈现"慢-快-慢"节律,符合"S"型生长曲线,采用Logistic模型拟合效果显著,相关系数均在0.96以上;苗高、地径生长量的实测值与理论值回归系数分别为0.995 9和0.931 7,生长模型分析可行。②根据拟合方程获得物候参数,把苗高和地径生长期划分为生长前期、速生期和生长后期。不同阶段苗高、地径生长起、止时间存在差异,并表现出苗高与地径的异速生长现象。速生期苗高生长在前,地径生长在后。③不同种群苗期生长表现存在变异,苗高生长在生长前期、速生期、生长后期的持续时间和日均生长量分别为:28～48 d、0.11～0.18 mm,45～68 d、0.25～0.44 mm,110～151 d、0.04～0.09 mm;地径在各阶段的持续时间和日均生长量分别为40～89 d、0.003～0.004 mm,58～80 d、0.007～0.011 mm,61～113 d、0.002～0.004 mm。④速生期内的生长量占总生长量的比例较高,苗高、地径生长量比例分别为57.34%～57.93%和57.29%～58.47%,速生期内的苗高、地径生长量与整个生长期内的苗高、地径生长量呈显著的正相关关系(R为0.999 8和0.998 8),速生期起始时间与结束时间也存在显著正相关关系(R为0.859 2和0.815 1)。可见,高山松在理论亲本种云南松生境下苗期表现出正常的适应性,较早进入速生期的能迅速占据生长空间而获得较高的生长量,但不同种群间存在明显地分化,这与高山松的杂交起源特性及不同种群复杂的遗传背景有关。

The research was conducted to reveal the seedling growth dynamic and variation of eight populations of Pinus densata under natural field environment in P. yunnanens/s habitat. Through the seedling height and the basal diameters growth of one-year P. densata, we analyzed the dynamic growth rhythm by the growth parameters simulated from the Logistic Model. Seedling height and basal diameters growth rhythm of one-year P. densata are ＂S-shaped＂ curves of ＂slow-fast-slow＂. The significant correlations between the simulated values and the measured values of seedling height and basal diameters are 0. 995 9 and 0. 931 7, respectively. The seedling process is divided into three stages by the growth parameters ： initiation stage, rapid stage and later stage of seedling growth. There are the allometry phenomenons on the growths of seedling height and basal diameters. There are different growth characteristics and varied growth parameters among populations. The duration and daily growth of three different stages are 28-48 days and 0.13-0.18 mm, 45-68 days and 0.28-0.44 mm, 110-151 days and 0.04-0.06 mm in seedling height, and 40-89 days and 0. 003-0. 004 mm, 58-80 days and 0. 007- 0.011 mm, 61-113 days and 0. 002-0. 004 mm in basal diameters, respectively. The growth rates of the seedling height and basal diameters are 57.34% -57.93% and 57.29% -58.47% , respectively, in the rapid stage compared with the whole period. By regression analysis, the relations between the seedling height and basal diameters growth in rapid stage and the whole period are linear positive correlations with R coefficients of 0. 999 8 and 0. 998 8, respectively. The signifi- cant correlations between the beginning and the end of rapid stage of seedling height and basal diameters are with R coeffi- cients of 0. 859 2 and 0. 815 1, respectively. Therefore, P. densata as a hybrid species shows normal adaptability in seed- ling growth in putative parental species P. yunnanensis habitat. The population early into the rapid stage of seedling growth gains fast growth through accessing available growth environment. The seedling growth and the population differentiation characteristics are related to the multiple hybrid origin and complex genetic background.