大豆育苗断根移植对植株生长发育特性的效应

本文采用育苗断根移植的方法研究了大豆植株的生长发育特性。切断主根解除了根的顶端优势,促使侧根大量形成。从分枝到鼓粒期,根容量、根干重均比对照高,到结荚期达到高峰,断根移植后增加了根瘤数量,特别是中小根瘤比对照增加明显,并提高了根瘤固氮活性,固氮量比对照增加3.6—5.5(mg/株·天),改进了大豆氮素供应状况。断根移植后还增加了叶绿素的含量,光合速率高,植株生长繁茂,表现单株鲜重、单株叶面积均比对照高。从产量构成因素看,断根移植后株高变矮,分枝数、单株荚数、单株粒数、百粒重均比对照明显增加,大豆产量可提高15％以上。

EFFECTIVENESS OF RAISING-SEEDLING AND ROOT-CUTTING TRANSPLANT OF SOYBEAN ON SPECIFIC PROPERIES OF GROWTH AND DEVELOPMENT OF PLANT

The specific properties of plant growth and development were studied by using method of raising-seedling and root-cutting transplant of soybean in this paper. The superiority of root top was removed and more branch roots were grown after root-cutting transplant. The capacity and dry weight of root were more than check through the stages of branch to seed filling and reached the highest amount in podding stage. No. of nodules increasing, especially medium and small nodules remarkable were more than check after root-cutting transplant. Activity and number of nitrogen fixing were increased and improved supply condition of soybean nitrogens, the chlorophyll content(dry weight %), photosynthetic rate, fresh weight of per plant, leaf area of per plant were more than check. In yield components, except plant height, No. of branch, No. of pod per plant, No. of seed per plant and weight of 100 seeds were clearly shown that was more than check and above 15% of soybean yield was increased.