杂交中籼稻长秧龄移栽的分蘖成穗特性

Tillering and earing characteristics of middle-season indica hybrid rice under long-age seedlings

以中籼迟熟杂交稻F优498为试验材料,采用三因素裂区设计,研究不同穴插苗数和水肥管理模式下长秧龄水稻的分蘖发生与成穗规律以及不同叶位与等级分蘖对产量贡献的影响.结果表明：长秧龄水稻分蘖能力强,分蘖发生和成穗的叶位多,且在65 d秧龄下不同水肥管理模式的分蘖能力强弱表现为干湿交替模式＞旱种模式＞淹灌模式；同时,在长秧龄下穴插单苗的各级分蘖发生率和成穗率都高于双苗.长秧龄水稻不同等级茎蘖对产量的贡献表现为1次＞2次＞主茎＞3次；不同等级茎蘖对长秧龄水稻产量构成因素的影响,整体上,穗粒数和千粒质量表现为1次＞2次＞主茎,结实率则是1次＞主茎＞2次.长秧龄水稻分蘖发生的优势叶位是1次分蘖1～9叶位,2次分蘖1～2和7～8叶位；分蘖成穗的优势叶位是1次分蘖2和7～9叶位,2次分蘖1～3和7～8叶位；对产量贡献的优势叶位是1次分蘖6～9叶位,2次分蘖1～2和7叶位；总体上,长秧龄水稻的优势分蘖叶位是1～2和7～9叶位,它们对产量的贡献之和达到了68.95％.延长秧龄,产量随之降低,但在长秧龄下穴插单苗,采用干湿交替灌溉模式仍然可以获得高产.

Summary Tillering and earing is a key factor for yield formation in rice and one of remarkable features of high‐yield colony , characterized by effective panicles per unit area . Transplanting seedling age is an important factor that may greatly affect tillering and panicle formation . Related researches have showed that by extending the transplanting seedling ages , the seedling quality would become worse;the tillering growth rate would slow down;the percentage of effective panicles would reduce;the numbers of effective panicle per plant and grains per panicle＆amp;nbsp;would decrease , resulting in obvious reduction of grain yield . Due to the special landscape of the hilly areas in China , the long transplanting seedling age still existed in those areas . To investigate the effect of different seedlings per hole and water‐nitrogen managements on tillering and panicle formation pattern under long seedling age , F you 498 was used as test material in this experiment . A three‐factor split plot was conducted with transplanting seedling ages as the main plot ;the water‐nitrogen management patterns as the secondary plot and seedlings per hole as the third plot . The aim was to provide the theoretical and practical data for improving the grain yield of long transplanting seedling age in hilly areas . The results showed that the tillering capacity of the older‐age seedlings was stronger , and the number of leaf positions of tillers and panicles were increased . And the tillering ability of different water‐nitrogen management patterns was controlled alternate irrigation pattern 〉 dry cultivation pattern 〉 submerged irrigation pattern under 65 d seedling age . Meanwhile , single seedling in a hole had higher percentage of emerging and earbearing tiller than double seedlings in a hole at older seedling age . At 65 d seedling age , the contribution for yield was the primary tiller 〉 secondary tiller 〉 main stem 〉 third tiller;and the grain number per panicle and thousand‐grain mass were primary tiller 〉 secondary tiller 〉 main stem , while the seed setting rate was primary tiller 〉 main stem 〉 secondary tiller . The superior leaf positions of emerging tiller of older seedling age were the first to ninth leaf for primary tiller , the first to second and seventh to eighth leaf for secondary tiller;the superior leaf positions of earbearing were the second , seventh to ninth leaf for primary tiller , and the first to third and seventh to eighth leaf for secondary tiller;the superior leaf positions of yield contribution were the sixth to ninth leaf for primary tiller , the first , second and seventh leaf for secondary tiller . It is concluded that the superior leaf positions of older seedling age rice are the first to second and seventh to ninth leaf , of which the total contribution to the yield reaches 68 .95% . With the extension of seedling age , the yield obviously decreased;however , applying to single seedling per hole in combination with controlled alternate irrigation pattern can improve the yield of long‐age seedlings effectively .