家蚕不同品种饲料效率的杂种优势的初步研究

A PRELIMINARY STUDY ON HETEROSIS OF VARIOUS SILKWORM BREEDS IN THEIR FEED EFFICIENCY

本实验用4个三元杂交种、2个二元杂交种和2个原种为实验材料,4龄起蚕开始饲养,以茧层转换率、近似消化率、丝长、丝量、干茧出丝率等为指标,分别对原种、二元杂交种、三元杂交种间的饲料效率进行比较研究,同时还对食下量、食下率近似消化量、近似消化率、茧层转换率进行方差分析和多重比较,得出以下结论:①二元杂交种的食下率、近似消化率高于三元杂交种,而三元杂交种又高于原种;②对于茧层转换率,三元杂交种高于二元杂交种,二元杂交种与原种之间差异不显著;③对于丝长、丝量,三元杂交种略高于二元杂交种,二元杂交种高于原种.因此,要提高茧层转换率,可以通过选择优良亲本利用杂种优势来实现.

Four triple hybrids, two double hybrids and two stock seeds of silkworm (Bombyxmori) were used in a rearing experiment to compare their cocoon shell transformation rate(cocoon dry weight/dry weight of food consumed), approximate digestibility [(dry weight offood consumed-dry weight of silkworm faeces) x 100% ],filament length,amount of silk pro-duction and silk production rate of dry cocoon (silk dry weight/cocoon dry weight X 100%).The data recorded were treated statistically with variance analysis and Duncan's multiplerange test. The results showed that the digestion rate and approximate digestibility werehigher in the double hybrids than in the triple hybrids and higher in the triple hybrids than inthe stock seeds. Cocoon transformation rate was higher in the triple hybrids than in the dou-ble hybrids,which were not significantly different from the stock seeds. Filament length andsilk amount in a reeling test were slightly higher in the triple hybrids than in the double hy-brids,which in turn had greater filament length and silk amount than the stock seeds. It istherefore concluded that improvement in cocoon shell transformation can be realized throughthe utilization of heterosis by proper parent combination.