水稻甬优12不同产量群体的株型特征

Plant-type Characteristics in Populations with Different Yield of Yongyou 12

以籼粳交超级稻甬优12为试材,比较研究高产（10.5-12.0 t hm^–2）、更高产（12.0-13.5 t hm^–2）、超高产（〉13.5 t hm^–2）3个群体的株型特征。结果表明,穗长、穗粒数、一次和二次枝梗数,超高产群体分别为21.56、356.34、20.46和73.98（两年平均值）,均高于对应的高产和更高产群体,但一次和二次枝梗的结实率略微降低。超高产群体上部三叶的长、宽以及卷曲率高,倒一、倒二、倒三叶的卷曲率分别为1.84、1.47、1.26,叶基角和披垂度小,抽穗后的主茎绿叶数多。超高产群体株高为143.50 cm,分别较更高产、高产群体高1.98%和3.83%,上部第一、第二、第三节间长度增加,穗长加穗下节间长占株高比例、穗下节间占秆长比例高,分别为39.84%和37.75%;基部第一、第二、第三节间长度缩短,茎秆粗度和茎壁厚度增加,茎、鞘干物重以及K、Si含量高,提高了基部节间的抗折力同时降低了倒伏指数。

Using indica-japonica super rice Yongyou 12, we compared the plant-type characteristics among three types of popula-tions （high yield： 10.5–12.0 t ha^–1; higher yield： 12.0–13.5 t ha^–1; super-high yield： 〉13.5 t ha^–1）. The main results indicated that in super-high yield population, the mean values of panicle length, total grains per spike, number of the primary and secondary ra-chises were 21.56, 356.34, 20.46, and 73.98, respectively, being higher than those in the high and higher yield populations. How-ever, the seed-setting rate in the primary and secondary rachises showed slight reduction. Super-high yield population had longer length, larger width and higher rolling rate, smaller leaf basic angle and dropping angle, more green leaves after heading for the top-most three leaves in comparison with the other two populations. Compared with the other two populations, super-high yield population had higher plant height, longer length of top three internodes, higher ratio of sum of panicle and neck internode to plant height 39.84% and ratio of neck internode to stalk length 37.75%. The decreased length of basal three internodes, increased culm diameter, culm wall thickness and dry weight of culm and sheath made higher anti-broken strength and lower lodging index in super-high yield population.