两优培九结实期植株体内细胞分裂素与叶片衰老的关系

两系杂交稻两优培九结实前、中期根系伤流液和叶片中的玉米素(Z)和玉米素核苷(ZR)含量与其父本扬稻6号无明显差异,但显著高于三系杂交稻汕优63;在灌浆后期,两者含量明显低于汕优63和扬稻6号.根伤流液和叶片中的Z+ZR含量与叶片叶绿素含量密切相关(r=0.88**～0.93**),表明植株早衰与根和叶片中较低的细胞分裂素有关.灌浆中、后期叶面喷施10-5mol·L-1的Z可明显提高两优培九叶片中Z+ZR的含量,延缓衰老并能提高结实率和粒重.     

几种细胞分裂素和生长素对杜仲下胚轴离体培养的影响

培养在附加不同种类的激素和不同激素浓度组合的 MS 基本培养基上的杜仲下胚轴切段,能诱导出愈伤组织,但诱导出的愈伤组织的生物产量及芽数不同:1.含0.2mgL~(-1)～2mgL(-1)BA 和2mgL(-1)ZT的 MS 培养基上,外植体诱导出了愈伤组织和芽,而在附加2mgL(-1)KT 的 MS 培养基上,外植体只能诱导出愈伤组织。2.在 MS+8mgL(-1)BA 的培养基上,只有愈伤组织的产生而无芽的分化,说明8mgL(-1)BA 抑制了芽的发生。3.MS+2mgL(-1)BA+0.2mgL(-1)生长素(NAA、IAA、IBA)的培养基,能促进外植体诱导出愈伤组织,也能分化出芽。     

Premature seed germination induced by very-long-chain fatty acids causes jelly seed disorder in the mango (Mangifera indica L.) cultivar ‘Amrapali’ in India

Jelly seed (JS) in ‘Amrapali’ mango (Mangifera indica L.) is a physiological disorder, the cause of which has long remained obscure. The disorder is distinguished by the appearance of jelly-like tissue in the pulp adjoining the stone, although the fruit show no external symptoms. The objective of this study was to determine the causative factor inducing the JS disorder in ‘Amrapali’ mango. Studies showed, for the first time, that JS in ‘Amrapali’ mango arose at the start of germination-associated events in the seed of developing fruit. The trigger for premature seed germination originated from reduced synthesis of very-long-chain fatty acids (VLCFAs) in the seed of developing fruit. This then promoted the production of cytokinins, leading to the onset of premature germination-associated events in the seed. Consequently, a large increase in the activities of pectinolytic enzymes in JS pulp occurred that led to the rapid degradation of pectin and excessive softening of the pulp, to the consistency of jelly. The application of plant growth regulators to developing fruit showed that gibberellic acid (GA₃) increased the incidence of JS, while paclobutrazol reduced the incidence of JS, confirming that the onset of early germination during fruit maturation and ripening played a primary role in the incidence of the JS disorder.     

‘巨峰’葡萄细胞分裂素氧化酶基因CKX3的克隆与表达分析

结合同源克隆和RACE技术在‘巨峰’葡萄（Vitis labruscana Bailey × V. vinifera L.‘Kyoho’）中克隆了细胞分裂素氧化酶基因CKX3,分析了该基因的表达特性及其对细胞分裂素的响应。序列分析表明,该基因cDNA全长为2 049 bp（GenBank登录号：KP689597）,ORF（开放阅读框）为1 569 bp,编码522个氨基酸,具有FAD（黄素腺嘌呤二核苷酸）结合结构域和细胞分裂素结合结构域。该基因定位在葡萄的7号染色体上,具有4个内含子,5个外显子。氨基酸序列多重比对和系统进化树分析显示‘巨峰’葡萄CKX3与荷花NuCKX3亲缘关系最近,与毛果杨同源性较高。基因表达分析结果显示‘巨峰’葡萄CKX3主要在根部和花序中大量表达,其次是在卷须和果实中有较高的表达,在茎和叶中的表达量较低;在花序发育过程中,在盛花期前表达量较低,盛花期以及盛花后表达量增加。在6-BA处理葡萄叶片后,CKX3的表达与细胞分裂素氧化酶的活性都高于对照。     

苹果细胞分裂素O–糖基转移酶基因MdZOG1的分离与功能鉴定

以‘嘎拉’苹果为材料,采用同源克隆和PCR技术分离了苹果细胞分裂素O–糖基转移酶基因MdZOG1。MdZOG1的开放阅读框(ORF)长度为762bp,编码含有253个氨基酸的蛋白。系统进化树分析显示,MdZOG1与PbZOG1亲缘关系最近。基因表达分析显示MdZOG1主要在苹果根和茎中表达,在花和果实中的表达量较低。通过农杆菌介导的遗传转化获得转MdZOG1拟南芥和烟草。干旱处理试验结果显示:超量表达MdZOG1显著提高拟南芥和烟草植株的抗旱能力,表明苹果细胞分裂素O–糖基转移酶在植物抗旱胁迫中发挥重要作用。     

杂环脲类细胞分裂素混剂对白肉火龙果经济性状的影响

以白肉火龙果为试材,探讨杂环脲类细胞分裂素混剂对果实经济性状的影响,结果表明:(1)果实纵横径和单果重均比对照有极显著的增加,以10 mg·L-1喷2次处理效果最好;(2)果实可溶性固形物(TSS)含量均极显著地高于对照,其中喷2次比1次效果好.     

Development of a regeneration protocol through indirect organogenesis in prickly pear cactus (Opuntia ficus-indica (L.) Mill)

An indirect organogenesis regeneration protocol for Opuntia ficus-indica (L.) Mill var “Blanco sin Espinas” is described. One centimeter square cladode explants sections from previously micropropagated prickly pear plants were cultured in Murashige and Skoog (MS) basal medium supplemented with 20 different combinations of 2,4-dichlorophenoxy acetic acid (2,4-D) and benzyladenine (BA). The best calli induction and regeneration response were observed when 2.26 μM 2,4-D and 2.21 μM BA combination was applied to the nopal explants. Regenerating calli was capable of forming new buds when transferred to MS basal medium supplemented with 0.5 μM BA (proliferation medium). Shoot elongation and rooting were achieved on MS medium without plant growth regulators. Excellent acclimatization to greenhouse conditions was observed for all transferred plantlets. By this procedure no morphological differences were observed between the regenerated and mother plants. This protocol may be also utilized to carry out plant regeneration after genetic transformation, in order to develop transformed plants without the presence of chimeric zones.     

喷施细胞分裂素类物质对地膜旱作水稻防衰及增产效应

利用随机区组设计，研究了在始穗期叶面喷施6-苄基腺嘌呤(6-BA)、6-糠胺基嘌呤、玉米素等3种细胞分裂素类物质对地膜早作水稻防衰及产量的影响。结果表明：6-BA能较好的防止地膜早作水稻早衰，增加有效穗数、穗实粒数和粒重，增产极显著，增产达15．94％，6-糠胺基嘌呤、玉米素则防衰及增产效果不显著。     

Cultural factors influencing adventitious shoot and plantlet formation from slash pine cotyledons

Cultural factors affecting in vitro shoot and subsequent plantlet formation of slash pine (Pinus elliotti Engelm.) cotyledons were investigated. Basal media composition, N⁶-benzylaminopurine (BAP) concentration and exposure time significantly influenced bud induction in cotyledons cultured under a continuous photoperiod of 35–40 mol m^–2 s^–1 at 24 ± 1 °C. The largest number of adventitious shoots was obtained after 28 days exposure to 66 M BAP-supplemented modified Gresshoff and Doy 1 (GD1) medium. Relatively high frequencies of large shoots were obtained after a 14-day exposure to 22 M BAP-supplemented Brown and Lawrence (BL) or 66 M BAP-supplemented GD1. Adventitious shoots derived from 21- or 28-day exposures to BAP developed more slowly and were smaller in size than those derived from a 14-day exposure to the cytokinin. Shoot differentiation and subsequent growth were also influenced by basal media, media concentration, and presence of activated charcoal in the medium. The percentage of cotyledons forming shoots was highest on half-strength GD1 medium containing activated charcoal. Rooting was achieved in vitro under a continuous photoperiod of 60–70 mol M^–2 S^–1. Roots were formed when excised shoots were planted on GD 1/2 medium supplemented with 2.68 M 1^–1 a-napthaleneacetic acid (NAA) with or without BAP for 14 days. The proposed technique of slash pine propagation using cotyledon explants can produce up to 100 seedlings per embryo.     

大花蕙兰的嫩根与根兜组织快繁技术研究

取大花蕙兰的的嫩根和根兜为外植体在MS培养基上用不同浓度的细胞分裂素BA和生长素NAA进行了研究。结果表明：根兜的分化率比嫩根高,而最适合的培养基配方为MS＋BA1.5 mg/L＋NAA0.5 mg/L＋蔗糖30 g/L＋琼脂8 g/L。可直接分化成小苗,增殖的同时可获得健壮的再生植株。最适的生根培养基为：MS＋NAA0.3 mg/L＋活性碳1.0/L＋蔗糖25 g/L＋琼脂7 g/L。