机插早稻分蘖成穗特性及基本苗公式参数研究

为精确定量机插早稻适宜的群体起点，合理利用分蘖成穗，以4个早稻(株两优30、株两优189、中嘉早17和嘉早311)品种(组合)为材料，研究了机插早稻分蘖成穗特性及基本苗公式参数。结果表明，机插早稻一次分蘖主要发生在主茎第3~6叶位，第4、第5叶位为分蘖发生与成穗的优势叶位；二次分蘖发生较少，以1/3、2/3、1/4为主，但均不能成穗；单株分蘖成穗数杂交稻约3.1个，常规稻约2.2个；主茎及优势蘖位穗部性状较好，产量高，对总产量贡献大。早稻在三叶期左右移栽，杂交稻移栽分蘖缺位叶龄(bn)为1.7~1.8，校正系数(a)为?1.2~ ?1.1，有效分蘖发生率(r)为0.75左右；常规稻bn为2.5~2.7，a为?1.3~ ?1.1，r为0.7左右。生产中机插早稻应在保证足够基本苗的基础上，争取分蘖早生多发，充分发挥优势叶位的分蘖成穗优势，并合理利用动摇分蘖成穗，以获取较多的有效穗而实现高产。

Tillering and Panicle Formation Characteristics of Machine-transplanted Early Rice and Its Parameters of Basic Population Formulae

To accurately determine planting density and make reasonably use of tillers for machine-transplanted early rice, we examined the tillering and panicle formation characteristics and the parameters related to basic population formulae with four early rice combinations (Zhuliangyou 30, Zhuliangyou 189, Zhongjiazao 17, and Jiazao 311). Results showed that the primary tillers of the machine-transplanted early rice initiated mainly from leaf 3 to leaf 6 on main stems with leaves 4 and 5 being the superior positions for tiller initiation and panicle formation. Secondary tillers initiated mainly in 1/3, 2/3, 1/4, but could not form panicles. The panicle number per seedling was 3.1 and 2.2 for hybrid rice and inbred rice, respectively. Panicles at superior leaf positions on both main stems and tillers showed better properties and higher productivity, thus making greater contributions to the yield. For hybrid rice mechanically transplanted at the stage with 3 to 4 leaves, the leaf age without tillering (bn) was 1.7 to 1.8, with the correction factor (a) of −1.2 to −1.1 and the percentage of productive tillers (r) of 0.75. For inbred rice, the bn, a, and r were 2.5 to 2.7, −1.3 to −1.1, and 0.7, respectively. In conclusion, in order to obtain a high yield of machine-transplanted early rice, the key strategy is to ensure a sufficient number of basic seedlings, and promote tillering as early and many as possible, whereby increasing the percentage of productive tillers.