关键词: 杉木, 无性系, 选择

Abstract: A clonal selection program of its genetic improvement had been conducted during 1981～1997 on Kaihua Forest Farm, Zhejiang Province. A multiple step clonal test and selection strategy or stepwise screening procedure was adopted to ensure accurate selection and rapid application of the best clones to plantations. The strategy included four test steps: (1)Selecting of plus individuals as ortests from the full-sib and half-sib progeny and provenance trials, and then cloning them by sproutings collected from trunk base in nursery for establishment of cutting garden. From them a lot of cuttings had been harvested for sequent tests; (2) Preliminary clonal test with a great number of clones by row plot with 5 ramets and 4 replications; (3) Second time clonal test with 15～20 clones selected from preliminary trials by row plot with 5～6 ramets and 4～6 replications; (4) Final clonal test with a few clones selected from second time test by block planting with 36～50 ramets and multiple replications to accurately examine their realized productivity. The selection criteria included growth rate, stem form, form ratio, crown form, bark rate, and resistibility. In every trial the seedlings of seed orchard and super provenance were used as controls. Generally, the selection was carried out at 4～6 years after planting. In order to accelerate the process of test and selection in favour of clonal plantation establishment as early as possible, every clonal test type may be set up simultaneously during successive years in several sites, if the clones display superior at preliminary test. In addition, a number of clones well displayed may involve simultaneously in several test trials for re-verification. Up to now 143 clonal trials with 257 clones and covering total of 81.6 hm² were established. Recently, 10 super clones were selected from original clones, based on performances on multiple step tests. The wood properties of five clones were measured. Results shown that their individual volume based on second time test and volume per unit area (hm²) based on final selection test were increased 60%～100% in comparison with the local seed orchard offsprings. However, the wood properties presented almost the same as control.

Key words: Chinese fir, Clone, Selection