Studies On Male Sterility System In Hexaploid Triticale With T.Timopheevi Cytoplasm

Triticale is a new species generated artificially by crossing rye to wheat and then doubling chromosome. It has many good characteristics in wheat and rye. The CMS is one of the main ways to make use of crop heterosis. Based on the principle materials which are male sterile lines and restorer lines of triticale with T.timopheevi cytoplasm breeded by our research group, three contents are studied in the research: 1.cytology identification of male sterile lines and restorer lines;2.studying the sterility characteristics of male sterile lines and restoring ability of restorer lines;3.studing the effects of T.timopheevi cytoplasm to some agronomic characteristics in triticale hybrids; 4.studing the heterosis and combining ability of male sterile system of triticale with T.timopheevi cytoplasm.1. The result of cytology identification of male sterile lines and restorer lines chromosome numbers in root tips showed that five male sterile lines A₁,A₂,A₃,A₄,A₅ and four restorer lines R₁,R₂,R₃,R₄ are all hexaploid.2. The result of two years investigation to sterile stability of male sterile lines showed that six male sterile lines used in our study are completely sterile; the result of study on fertility restoring ability in F₁ showed that the fertility of male sterile linesA₁,A₂,A₄ can be restored easily; The fertility restoring ability of restorers lines R₁ is the best, and R₃ is lower than other. On the other hand, the xenial characteristics of parent and hybrids of triticale with T.timopheevi cytoplasm.3. The effects of T.timopheevi cytoplasm is studied by analyzing the performances of nine agronomic characteristics in triticale hybrids with T.timopheevi and normal cytoplasm, the experiment designs in blocks split, the parents are four male sterile lines and four restorer lines, there are 32 combinations with different cytoplasm. The result showed as follows: the heading dates of hybrids with T and A cytoplasm are significant different, the hybrids with T.timopheevi cytoplasm headed earlier; the plant height of hybrids with T cytoplasm is higher than that with normal cytoplasm; grains per spike and number of spikelets and seed setting rate is reduced by effect of T.timopheevi cytoplasm; fruiting spikes and spike length; grain yield per plant of hybrid with T.timopheevi is not be effected by T.timopheevi cytoplasm, 1000-kernel weight of hybrids with T.timopheevi is higher than normal triticale.4. Analisis on heterosis of eight agronomic traits in F₁ hybrids was carried out in a 3×3uncomplete diallele cross including three male sterile lines and three restorer lines with T.timopheevi cytoplasm. Many traits tended to the parent with low value or average value except thousand kernel weight, however there are significant differences among combinations. It showed us The analysis of combining ability showed that both gene additive effects and non-additive effects affected characters of F| hybrids, but thousand kernel weight was mainly controlled by the latter. The GCA effects of sterile lines Ai> A2 and restorer lines Ri >R.2 were higher than others in many traits, and might be good sources of parents. The relations between the mean of traits in Fi, heterosis of Fi hybrids, GCA effects and SCA effects were analyzed in the paper. The mean of characters in F| was positively related to the sum of GCA effects and SCA effects at different levels, and so heterosis of Fi was.