Selection Of Superior Clones From Second Generation Seed Orchard Of Larix Principis-rupprechtii

Larix principis-rupprechtii is an important economic and ecological forest species in North China.Seed orchard is an important way to provide good species.In order to improve the production efficiency of Larix principis-rupprechtii seed orchard,shorten the breeding period,superior clones with high yield and good sowing quality can be selected to improve the excellent building materials for seed orchard regeneration and establishment of high-generation seed orchard.In this paper,relevant studies were carried out on progeny growth and seed bearing performance of seed orchard mother trees,and superior clones were selected with excellent progeny growth and seed orchard mother trees bearing performance,and high genetic diversity were screened by EST-SSR molecular marker technology.The main results were as follows:1.There were significant differences in tree height,DBH,volume growth characteristics,trunk straightness,branch angle,branch thickness and other tree shape indexes among the half-sibling families of the second generation orchard of Larix principis-rupprechtii.Therefore,it is possible to select excellent families according to the growth characters and tree shape index of half-sib.At the selection rate of 0.60,17 families were selected,namely 111,120,100,59,96,78,77,119,79,42,86,76,82,97,68,35 and 116.2.There were significant differences in seed yield,1000-seed weight,plumpness,germination rate and other indexes among the 29 clones in the second generation orchard of Larix principis-rupprechtii,indicating that they has great selection potential.A total of 17 clones of 42,65,110,53,35,50,46,111,76,72,82,77,52 59,120,66 and 79 were selected at the selection rate of 0.60.3.Nine superior clones(111,120,59,77,79,42,76,82,35)with excellent progeny growth and stable production performance were selected.The genetic gains of tree height,DBH,volume and seed yield of 9 superior clones were 9.02%,10.56%,30.06% and 19.37%.There was no significance in genetic diversity between 9superior clones and 40 clones in the second generation orchard of Larix principis-rupprechtii thorough using EST-SSR molecular marker technology analysis.It provides the core germplasm resources and building materials for the construction of next generation seed orchard of Larix principis-rupprechtii.