白桦不同杂交组合三倍体子代当年生苗木生长性状分析

为了选择白桦三倍体杂种子代的优良杂交双亲和杂交组合，以4株中国白桦四倍体（Q14、Q19、Q33和Q34）为母本，5株杂种二倍体（M1、M2、M3、M4和M5）为父本，按测交系交配设计获得了20个杂交组合的白桦三倍体苗木，对各杂交组合三倍体子代的苗高和地径进行方差分析和配合力分析。结果表明，白桦三倍体家系间的苗高和地径均存在着极显著的差异，苗高和地径的一般配合力和特殊配合力的差异也达到了极显著水平。根据白桦各三倍体家系的生长量、一般配合力和特殊配合力，初步选择Q19和Q34为优良四倍体母本，M1和M2为优良二倍体父本，Q34×M2和Q34×M1为优良杂交组合。 

Growth traits of triploid progenies in one year old from different crosses of Betula platyphylla Suk.

Triploid progenies of 20 crosses were obtained by controlled-pollination using four autotetraploid Betula platyphylla ( Q14,Q19,Q33 and Q34 ) as female and five diploid hybrid B. platyphylla × B. pendula ( M1,M2,M3,M4 and M5) as male and tested in a nursery. This paper presents early growth measurements and the results indicat that cross had a significant effect on height and base diameter growth. Variances of general combining ability and specific combining ability for both height and base diameter were significantly different from zero. Based on the results of growth,general combining ability and specific combining ability,two autotetraploids( Q19 and Q34) were identified as good female parents, two diploid hybrids ( M1 and M2) as male parents,and Q34 × M2 and Q34 × M1 as the best crosses.