排序方式: 共有44条查询结果,搜索用时 31 毫秒
1.
以郑单958、丹玉39为试材,研究播种期对玉米生育期、籽粒灌浆速率、农艺性状和产量的影响。结果表明:在不同播期条件下,郑单958均比丹玉39生育期少12d左右,且播种越晚,生育期越短;两品种相同播期的灌浆速率变化规律一致;郑单958的千粒质量、穗粒数、株高、穗位均低于丹玉39;5月14日播种的玉米产量最高。 相似文献
2.
3.
4.
对郑单14的密度、播期及生理特点等一系列研究表明,郑单14的最适播种密度为52 500~60 000株/hm2;理想播期为5月25日至6月5日,不宜在6月10日以后播种.其表现高产稳产的主要生理原因是①叶面积指数变化合理,叶片持绿时间长,衰老慢,叶绿体中的光合色素、蛋白质和可溶性糖含量高;②过氧化物酶活性高,丙二醛积累少,光合效率高;③子粒体积大,灌浆时间长,千粒重高. 相似文献
5.
K. Ura S. Mizuno T. Okubo Y. Chida N. Misaka S. Adachi K. Yamauchi 《Fish physiology and biochemistry》1997,17(1-6):397-403
Changes in immunoreactivity of Na+/K+-ATPase -subunit in gill sections of wild masu salmon (Oncorhynchus masou) during the parr-smolt transformation (smoltification) were compared with changes in gill Na+/K+-ATPase specific activity. Gill Na+/K+-ATPase specific activity increased from April and peaked in May. Immunohistochemical analysis, using an antiserum against a synthetic oligopeptide based on the conserved region of the Na+/K+-ATPase -subunit, revealed that immunoreactivity was confined to chloride cells in the surface layer of primary lamellae and the proximal end of secondary lamellae. The size and number of these cells increased gradually from February to May; however, the number of chloride cells of the secondary lamellae decreased in May. These data suggest that the synthesis of Na+/K+-ATPase and the proliferation of chloride cells occur prior to the elevation of enzyme activity. Moreover, it is likely the proliferation and hypertrophy of chloride cells on primary lamellae prepare smolts for entry into seawater and migration in the ocean. 相似文献
6.
7.
8.
9.
10.