基因型与环境互作条件下凡纳滨对虾多性状复合育种方案的遗传和经济评估

Genetic evaluation and investment appraisal of the multi-trait selection breeding program in Litopenaeus vannamei

为预测和评估目标性状[收获体质量(BW),存活率(SR)和饲料摄入量(FI)]的遗传进展及经济效益,实验依据凡纳滨对虾多性状复合育种方案进行模拟选择了20个世代。此外,实验还利用选择指数理论,估计目标性状的选择反应、遗传进展以及育种目标;并对影响利润(RP)和效益成本比率(BCR)的生物学参数(遗传力、育种目标是否包括FI),经济学参数(对虾价格、饲料价格、贴现率、初投资、年费用)和运行参数(首次回报年份、扩繁效率)进行了敏感性分析。结果表明,在基础参数值下,BW、SR和FI每个世代的选择反应分别为0.86 g,4.70%和1.54 g;育种方案执行20年产生的RP和BCR分别为862 747.91万元和844.26;敏感性分析显示,在所有参数中,扩繁效率对RP和BCR的影响最大。基因型与环境互作的敏感性分析表明,重排效应(养殖环境对同一基因型个体在不同环境中育种值排序的影响)对RP和BCR的影响较大。尺度效应(养殖环境对遗传方差的影响)对RP和BCR的影响不如重排效应明显。研究表明,从遗传学和经济学角度考虑,如果育种目标性状在不同的区域间存在较强的基因型与环境互作效应,应针对不同的环境设置多个独立的育种核心群体,以期获得更高的RP和BCR。

The genetic gain and economic benefit from a multi-trait breeding scheme with Litopenaeus vannamei were calculated after performing 20 selections. The breeding object was made up of harvest body weight（BW） ,survival rate （SR）and feed intake （FI）, but the trait FI was not included in the selection index. Selection response and genetic gain of the breeding object were estimated based on selection index theory. Economic benefit was predicted after nucleus shrimp was multiplied by a pyramid breeding structure （nucleus,multiplication and production populations）. The sensitivity of profit （RP） and benefit/cost ratio （BCR） to a number of factors was examined. It comprises biological parameters （heritability value, accounting for feed intake）, economic parameters （price of shrimp, price of feed, discount rate, initial investment, annual cost ）, and operational parameters （year when first return occurs, multiplication efficiency）. For the base situation, selection responses on BW, SR and FI for the base situation were 0.86 g, 4.70% and 1.54 g,respectively; the RP and BCR of this program were CNY 8627.48 million and 844.26 after performing 20 selections. The greatest contribution to variations in RP and BCR came from the improvements in the multiplication efficiency at the level of both the nucleus and the hatcheries. The sensitive analysis of G x E interaction showed that re-ranking effect had more significant effect than the scale effect on RP and BCR. If there were significant differences between culture environments and environment in the breeding center, independent breeding projects were suggested for governments or corporations from an economic viewpoint.