水稻突变体W33高位分蘖特性利用价值研究

为探讨水稻突变体材料W33高位分蘖特性在水稻育种上的利用价值。以野生型水稻恢复系R818及其高节位分蘖突变体W33为试验材料,用盆栽试验研究R818和W33的植株、分蘖和穗部性状差异,用大田栽培控制性试验比较R818和W33分蘖、产量构成性状及子粒产量差异,测得参试材料各性状数据。结果表明,生长前期W33和R818株高、主茎叶均长无明显差异,中后期二者株高、主茎叶均长渐显显著或极显著差异;W33单株平均分蘖数是R818的7.5~8.8倍,平均有效穗数是R818的8.6倍,分蘖平均成穗率与R818相当,但单穗穗长、枝梗数和着粒数明显低于R818,而千粒重与R818无明显差异;W33和R818单株籽粒产量均随密度增大而降低,并以最低密度条件下最高,最高密度条件下最低;尽管W33单穗产量明显低于R818,但在相同栽插密度条件下,W33和R818群体产量差异不显著(F=3.7868<F_0.05,1,4);在一定密度范围内,W33能充分发挥其旺盛的分蘖力和较高的成穗率优势,以弥补单穗产量较低的缺陷,其群体产量最终达到与R818相当的水平。说明W33旺盛的分蘖力和较高的分蘖成穗率特性在水稻育种上具有一定的利用价值。

Higher-nodal-position Tilling Traits of Rice Mutant Material W33: Study on the Utilization Value

The aim is to explore the utilization value of high tillering characteristics of rice mutant material W33 in rice breeding. Wild-type rice restorer line R818 and its mutant W33 with higher-nodal-position tillers were served as the test object, and potting experiment was used to study the difference of plants, tiller and panicle traits of R818 and W33, the difference of tiller, yield composition characters and grain yield of R818 and W33 were compared by field cultivation experiment, the character data of the test materials were measured. The results showed that there was no significant difference in plant height and average leaf length of main stem between W33 and R818 at the early stage of growth, and however there was significant or extremely significant difference in plant height and average leaf length of main stem between the two in the middle and late period; the average tiller number per plant of W33 was 7.5-8.8 times that of R818, the average effective panicle number of W33 was 8.6 times that of R818, and the average percentage of earring-tillers was equivalent to that of R818, but the length of single panicle, the number of branches per panicle and the number of grains per panicle were much lower than those of R818, while the 1000-grain weight slightly differed from that of R818. The grain yield per plant of W33 and R818 decreased with the density increased, it was the highest when the density was the lowest, and it was the lowest when the density was the highest. Although the yield per panicle of W33 was much lower than that of R818, there was no significant difference of population yield of W33 and R818 under the same density (Fvalue=3.7868<F_0.05,1,4). Within a certain density range, the advantages of vigorous tillering ability and higher spikes rate of W33 could be fully demonstrated to make up for its disadvantage of low yield per panicle, and its population yield could finally reach the level equivalent to that of R818. It is suggested that the characteristics of stronger tillering ability and higher spikes rate of W33 should have certain utilization value in rice breeding.