Chatterjee S N, Mohandas T P
SeriBiotech Laboratory, Central Silk Board, Kodathi Campus, Sarjapur Road, PO: Carmelram, Bangalore 560 035, Karnataka, India.
Genome. 2003 Jun;46(3):438-47. doi: 10.1139/g03-024.
Bombyx mori L., commonly recognised around the world as the mulberry silkworm, is characterized by a wide variability in yield and developmental traits, which have been proven through conventional genetic analysis to be of polygenic nature. A large number of morpho-biochemical traits and RFLP and RAPD markers are mapped on different linkage groups, but to this point very little attention has been given to unravelling the genetics of yield traits. To address this issue, polymorphic profiles of 147 markers generated with 12 ISSR primers on the genomic DNA of 20 silkworm stocks of diverse yield status were subjected to multiple regression and discriminant function analyses (DFA). This led to the identification of eight markers generated by six primers, which demonstrated high beta-coefficient indices of -0.451 to -0.940. Furthermore, a significant difference between the yield traits for stocks with and without the specific marker could also be established. The inheritance pattern of one marker, L13800bp, identified at the first step of selection of markers through stepwise regression analyses for five yield parameters is discussed in the context of applying multiple regression analysis for establishing association, if not linkage, between a group of DNA markers and a particular yield trait of polygenic nature and using such markers in molecular marker-assisted breeding programs.
家蚕（Bombyx mori L.），在全球普遍被认为是桑蚕，其产量和发育性状具有广泛的变异性，通过传统遗传分析已证明这些性状具有多基因性质。大量形态生化性状以及RFLP和RAPD标记被定位在不同的连锁群上，但到目前为止，在解析产量性状的遗传学方面很少受到关注。为解决这个问题，利用12条ISSR引物在20个不同产量状态的家蚕品系的基因组DNA上产生的147个标记的多态性图谱，进行了多元回归和判别函数分析（DFA）。这导致鉴定出由6条引物产生的8个标记，其β系数指数高达-0.451至-0.940。此外，还能确定具有特定标记和不具有特定标记的品系在产量性状上存在显著差异。在通过逐步回归分析对五个产量参数进行标记选择的第一步中鉴定出的一个标记L13800bp的遗传模式，是在应用多元回归分析以建立一组DNA标记与多基因性质的特定产量性状之间的关联（如果不是连锁关系）并在分子标记辅助育种计划中使用此类标记的背景下进行讨论的。
