凯普克对马铃薯的增产效果研究

为探索天然植物生长调节剂凯普克对马铃薯的增产效果,在同等施肥条件下进行两个马铃薯品种田间试验。结果表明:凯普克处理的马铃薯单株结薯数多,两个试验点比对照每株分别增加0.4和0.7个;凯普克处理大薯比例高,分别提高3个和4个百分点;产量增加,凯普克处理增产幅度分别为22.5%和19.2%。投入产出分析表明,所有试验点凯普克处理的产出都比对照高,每公顷增加收益分别为6 256和6 993元。凯普克在马铃薯种植中使用可行,可进一步扩大推广。     

Grain yield,nitrogen use efficiency and physiological performance of indica/japonica hybrid rice in response to various nitrogen rates

Utilizing the heterosis of indica/japonica hybrid rice (IJHR) is an effective way to further increase rice grain yield.Rational application of nitrogen (N) fertilizer plays a very important role in using the heterosis of IJHR to achieve its great yield potential.However,the responses of the grain yield and N utilization of IJHR to N application rates and the underlying physiological mechanism remain elusive.The purpose of this study was to clarify these issues.Three rice cultivars currently used...     

竹子开花人工诱导与逆转研究现状及前景

竹类植物是重要的禾本科经济植物。由于开花周期长且难以预测,大多数竹种终身一次开花并导致死亡,具有自然结实率低等独特的开花习性,使得竹子开花及相关研究受到了很大的限制。通过竹子开化的人工诱导与逆转的研究,不仅可以人工获取难得的竹子种子,更为竹种分类鉴定、杂交遗传能种和开花机理等多方面研究工作提供了良好的基础,其理论意义和应用价值都十分重大。迄今为止,印度和比利时等国研究人员已在至少８个竹种中成功诱导     

Clonal propagation of rice through proliferation of axillary shoots

Summary Shoot base segments have been explanted from seedlings of rice (Oryza sativa L. subsp. Japonica, cv. Arborio) and grown on agar-solidified MS medium supplemented with different concentrations of four cytokinins: kinetin, BAP, 2iP and zeatin. After one month, segments were explanted from proliferated shoots and subcultured on their respective media. BAP was by far the most effective in inducing shoot proliferation. Highest rates were achieved at the higher concentration used: 5 mg 1^–1. Shoot base segments were subcultured fifteen times consecutively on seven different concentrations of BAP. Shoots grown in the presence of 5 mg 1^–1 of BAP proliferated an average of 12 normal shoots for each base segment throughout the fifteen subcultures. The shoots rooted easily on hormone-free medium. The technique does not require any particular skill, it is very effective and, therefore, can be suggested as suitable for clonal propagation of rice.     

Clonal propagation of Triticum durum Desf. from immature embryos and shoot base explants

Summary Immature embryos from five durum wheat cultivars were grown on Murashige and Skoog medium supplemented with two concentrations of kinetin or 6-benzylaminopurine (BAP). The embryos cultured on the medium containing 5 mg/l of BAP proliferated several axillary shoots. Shoot base segments subcultured on the same medium gave more shoot proliferation. The shoots developed into ear-bearing plants. This technique could be used for clonal propagation of wheat.     

Hormonal Control of Dormancy

Abstract

Changes in the equilibrium of almost all known phytohormones are correlated with the onset, maintenance and removal of dormancy in seeds, buds, bulbs and tubers, but the results are often contradictory. At present, there is no consistent theory which would explain the mechanism of hormonal control of dormancy. Also, the molecular regulation of dormancy is poorly understood.     

中国李组织培养过程中褐变的抑制研究

研究了影响中国李(海湾红宝石)Prunus salicina Lindl.cv.Gulf ruby茎段培养褐变的因素,包括基本培养基组分、抗氧化剂、细胞分裂素等.结果表明,WPM作为基本培养基培养效果较好;维生素C1.0g·L-1有效抑制褐变(褐变率16.7%),且能明显促进增殖(增殖倍数3.00)和生长;KT0.5～1.0mg·L-1外植体生长良好,褐变减轻.适宜的培养方案为WPM IBA 0.1mg·L-1 6-BA/KT 0.5～1.0mg·L-1 Vc 1.0g·L-1,低温弱光下培养7d后转入光下继续培养.     

三种细胞分裂素对苎麻愈伤组织诱导及分化的影响

3种细胞分裂素对苎麻愈伤组织诱导效应的研究结果表明:6-BA是最有利于苎麻脱分化的细胞分裂素类物质,而以ZT、KT为细胞分裂素的培养基中均不能使愈伤组织再分化。在分化培养基中加入AgNO3和AC能提高愈伤组织分化率,促进愈伤组织颗粒化,加入CM、CH能加速愈伤组织增殖,使其色浅,生命力强;但加入TJ和YE不能使愈伤组织分化,而且YE对苎麻愈伤组织生长有副作用。     

Floral induction in longan (Dimocarpus longan, Lour.) trees: IV. The essentiality of mature leaves for potassium chlorate induced floral induction and associated hormonal changes

This study was conducted to elucidate the function of leaves and their role in the alteration of plant hormone homeostasis during potassium chlorate (KClO₃) induced “off season” floral induction (FI) of longan. KClO₃ application had almost no effect on the concentration of gibberellins in receptive apical and lateral shoot meristems, whereas the auxin IAA initially decreased, but later remarkably increased. The most significant changes caused by KClO₃ treatments was an increase in zeatin/zeatin-riboside (Z/ZR) type cytokinins (CKs) 8 days after treatment in the shoot apical and close by lateral buds as well as in the tissue beneath these buds. The 6–7-fold increase in CK concentrations were greatly reduced in the absence of leaves (leaves removed between the apical bud and a girdle). A significant exception was a strong accumulation of isopentenyl adenine/isopentenyl adenosine (iP/iPA) type CKs in wood and bark beneath the bud of defoliated shoots that were isolated against the rest of functional leaves of the tree by a girdle. This accumulation of iP/iPA, the immediate precursors of Z/ZR, together with the strong increase of Z/ZR in the shoot apical bud (SAB) after KClO₃ application indicate that leaves may be involved in the biosynthesis of CKs. Overall, the results suggest that cytokinins play a significant role in KClO₃ induced “off season” floral induction in longan. This role may not be restricted to the biosynthesis of these hormones but also to their mobilization and accumulation in the SAB of newly flushing shoots.