|
Covering the ground with plastic film of Brassica pekinensis Rupr. accelerated the growth of root systems, increased root activity of chinese cabbage. At 92 days after seed sowing, The number of roots increased 22.6—24.2%; The diameter of roots increased 5.4—5.7%; root weight increased 15.85—18.89%; amount of bleeding increased 13.46—38.95%; and the active absorption surface of root system increased 47.7—67.5%. as Compared with control. Ground cover with film also promoted the growth of aerial parts, increased... Covering the ground with plastic film of Brassica pekinensis Rupr. accelerated the growth of root systems, increased root activity of chinese cabbage. At 92 days after seed sowing, The number of roots increased 22.6—24.2%; The diameter of roots increased 5.4—5.7%; root weight increased 15.85—18.89%; amount of bleeding increased 13.46—38.95%; and the active absorption surface of root system increased 47.7—67.5%. as Compared with control. Ground cover with film also promoted the growth of aerial parts, increased the leef surface and photosynthetic intensity. At 45 days after seed sowing, in comparison with control, weight of whole plant increased 100%; leaf surface increased 25.99—59.35%, as compared with control. During 42—72 days after seed sowing, the net photosynthetic rate increased 9.5—44.9%. It is considered that the above advantageous influences of film cover caused the yield increased 21.72—25.82%(average increment of yield per hectare is 18.75 tons). the quality of the cabbage was also higher. 大白菜地膜覆盖栽培,能够使根系生长加速、活力增强。在播种后92天和对照相比,根系增多22.6—24.2%;根茎直径增加5.4—5.7%;根重增高15.85—18.89%;伤流量增加13.46—38.95%;根系活跃吸收面增大47.7—65.5%。地膜覆盖对大白菜地上部的生长、叶面积增大及光合强度亦有较大的促进。播后45天的大白菜全株重量比对照增加100%叶面积增大25.99—59.35%;播后38—68天之间净光合率增高9.5—44.9%。由于覆盖大白菜具有上述良好作用,最后引起产量提高21.72—25.82%(每公顷平均增产18.75吨),同时也提高了大白菜的品质及等级。 This paper deals with the morphological and anatomical structure of soybean varieties which have different drought resistance in the field condition.The main results were as follows:As compared with drought sensitive varieties,the drought resistance varieties of soybean were characterized as that,their seeds germinated fast and the seedlings sent out more seconday-roots; their roots grew more quickly and the root system well developed which main root penetrated deeply in soil.As much more root quantity distributed... This paper deals with the morphological and anatomical structure of soybean varieties which have different drought resistance in the field condition.The main results were as follows:As compared with drought sensitive varieties,the drought resistance varieties of soybean were characterized as that,their seeds germinated fast and the seedlings sent out more seconday-roots; their roots grew more quickly and the root system well developed which main root penetrated deeply in soil.As much more root quantity distributed in deep soil,the root systems were belonged to "deep root type",The root system had.higher dry matter content and larger active absorbing surfance.The conducting tissues of foot system ware well developed because more vessels in it. 1985—1986年,我们分别观察研究了夏播和春播大豆不同抗旱品种的根系形态及解剖组织结构,结果表明,在北京地区,大豆抗旱品种根系的主要性状是:幼苗发根力强,根的生长速度快;主根扎得深,根系发达,根的干物重大,深层根量多,属于“深根型”;根系活跃吸收表面积较大;根的输导组织较发达. The results of experiments in 1987~1989 showed that moderate water stress inhibited growth and development of maize varieties at different stages. But variety Yuyu 3 posessed stronger ability to resist drought. Its leaf area, dry matter, the ratio of shoot to root and active absorption area of root decreased less under drought condition. Drought at seedling stage enhanced root growth of varieties, and increased adaptation ability. The ability to resist drought dropped down after shoot elongation, especially... The results of experiments in 1987~1989 showed that moderate water stress inhibited growth and development of maize varieties at different stages. But variety Yuyu 3 posessed stronger ability to resist drought. Its leaf area, dry matter, the ratio of shoot to root and active absorption area of root decreased less under drought condition. Drought at seedling stage enhanced root growth of varieties, and increased adaptation ability. The ability to resist drought dropped down after shoot elongation, especially during the stage of sexual organ formation when drought caused serious injry and significant decrease of yield. Drought resistance of a variety was mainly expressed by the ability to resist drought from shoot elengating to flowering. 1987~1989年试验结果表明,中度水分胁迫对玉米不同品种各生育时期生长发育均有抑制作用,但抗旱性较强的豫玉3号等品种,在干旱条件下可通过叶面积、干物重、根量和根系活跃吸收表面积减少幅度小,促进雌雄穗分化和发育顺利进行,因此生长发育和产量形成受干旱影响较轻。所有品种苗期适度干旱可促进根系生长,且表现有较强的适应干旱的能力,但拔节后抗旱力减弱,尤其在性器官形成期受干旱损伤最重,减产最大。一个品种的抗旱性的表现主要取决于拔节以后,孕穗期—开花期对干旱抵抗能力和产量的高低。
|