八倍体小偃麦与普通小麦杂交后代主要性状的遗传特点

STUDIES ON THE INHERITANCE OF THE MAIN TRAITS OF THE HYBRID PROGENIES BETWEEN 8X TRITITRIGIA AND TRITICUM AESTIVUM L.

本试验以八倍体小偃麦为桥梁亲本与普通小麦进行杂交,研究了不同杂交方式的当代结实率,不同杂种世代的育性和若干性状的遗传特点。结果表明:1.八倍体小偃麦与普通小麦没有明显的杂交不亲和性;2.杂种后代的育性随着自交和回交世代的增进而逐渐提高;3.杂种(F_1)的株高与双亲平均值相近,F_1的抽穗期具有明显的倾早性,F_1的穗长和每穗小穗数高于双亲平均值;4.杂种后代变异类型丰富,可以分离并选育出抗病、矮杆、强杆、大穗多花等优良类型,丰富育种的种质资源。因此,利用八倍体小偃麦与普通小麦杂交,是将偃麦草的遗传物质导入普通小麦,选育具有偃麦草优良特点的种质材料的有效方法。

The octoploid Trititrigia used as a bridge parent was crossed with common wheat (Trticum aestivum L.), and the seed setting frequencies of different crossing modes in each generation, fertility and inheritance of many characters in different hybrid generations were studied in the present experiment. The main results from this study are these: 1) no apparent crossing incompatibility is found in the crosses made between the 8X Trititrigia and common wheat; 2) the fertility of the hybrid progeny increases with each generation produced by selfing or backcrossing; 3) plant height of F_1 hybrids is close to the mean value of both parents, the time of spike emergence of F_1 hybrids is less than the mean value of the two parents while spike length and number of grains per spike is higher than the mean value of the two parents; 4) genetic segregation in hybrid progenies a broad range of variants; many segregants show superior traits, e.g. disease resistance, dwarf plants with strong stems, huge spikes with increased numbers of florets. Many new types can be se lected from the hybrid progenies. The conclusion from our study is this: our technique is a very effective way to transfer superior genetic information from 8X Trititrigia to common wheat; selection of superior germ plasms, with new and desirable trains can be carried out in the lines bred from the F_1 hybrids.