内源激素对黄姜体细胞胚发生的影响

以不同的培养基诱导外植体以建立优良的体细胞胚胎发生系统,并结合其发育过程中内源激素含量的动态变化,进一步探讨黄姜体细胞胚胎发生机理。选择2a生新鲜优良盾叶薯蓣41号,取以腋芽萌发而来的无菌枝条切段,采用MS+BA 1.5 mg/L+NAA 0.5 mg/L、LS+BA1.5mg/L和l/2 MS+NAA 1.0mg/L为诱导培养基,对培养过程中的内源激素的动态变化进行了分析。结果表明,高含量的生长素（IAA）、细胞分裂素（Z、ZR）和赤霉酸（GA3）有利于胚性细胞的形成。可为黄姜愈伤组织及体细胞胚胎形成的调控作用提供理论的参考依据,也可为其它植物的组织培养提供参考。     

Overcoming seed dormancy in oilseed rape (Brassica napus L.) with exogenous compounds

Dormant seeds of oilseed rape (OSR) can persist in the soil and cause OSR volunteers in subsequent crops. Several approaches were tested in the laboratory and in the field to determine whether dormancy induction and seed persistence can be reduced by using dormancy‐breaking exogenous compounds. In a laboratory experiment, OSR seeds were coated with KNO₃, micronutrients, or gibberellic acid (GA) prior to a secondary dormancy test. In a field experiment, seeds were coated in a manner analogous to the laboratory experiment, and then buried 10 cm deep in the soil for 2.5 months. In a practical demonstration, OSR plants were sprayed with either urea ammonium nitrate (UAN) or a commercial product containing GA prior to seed maturity. Seed coating (laboratory and field experiments) reduced secondary dormancy and seed persistence in the field by up to 99%. The efficiency of the treatments for mitigating secondary dormancy (laboratory and field experiments) in decreasing order was GA > micronutrients > KNO₃ > control. With pre‐maturity spraying (practical demonstration), UAN reduced primary dormancy by up to 77% and the development of secondary dormancy by up to 38%; GA had no effect. Dormancy and seed persistence of OSR seeds may be reduced by a pre‐maturity UAN treatment of OSR mother plants, or by applying appropriate exogenous compounds to OSR seeds.     

春石斛春化过程中生理生化的变化

将春石斛（Den.pink BeautyQueen'Den.pinkGem Elegance'）在【（22土）℃,10h/【（10土）℃,14h】（白天/晚上,下同）条件下处理,处理时间分别为∶10,20,30,40d,然后将材料置于【（23担）℃,10h】/【（18±1）℃,14h】条件下继续生长。结果表明,春石斛在30d完成春化,芽诱导率达98%,且100%为花芽;未完成春化的植株,芽诱导率低,且大部分发育成叶芽。在春化诱导前期,净光合速率增加,可溶性糖含量增加,内源激素GA。含量随处理时间延长而增加,在30d达到最大,ABA 在20d达到最高,比处理前高4倍多,表明春化促进内源激素GA和A BA的积累。     

铅胁迫对黄瓜幼苗内源激素积累动态的影响

以黄瓜幼苗为材料,采用高效液相色谱法,研究了铅胁迫对黄瓜幼苗生长和黄瓜幼苗中内源激素的影响．结果表明,低质量浓度铅（100mg／L）对黄瓜幼苗早期生长有着促进作用,铅质量浓度高于200mg／L时对黄瓜幼苗早期生长有着抑制作用,且铅质量浓度越高,对黄瓜幼苗生长的抑制作用越强．黄瓜幼苗内源激素水平在不同的组织中表现出不同的变化规律：根中脱落酸（ABA）的含量变化与铅质量浓度呈正相关;叶中赤霉素（GA3）的含量变化与铅质量浓度呈正相关;根和叶中生长素（IAA）的含量变化在铅质量浓度高于200mg／L时与其质量浓度呈负相关．IAA／ABA值与黄瓜幼苗生长有一定的相关．     

Plant growth-promoting rhizobacteria-alleviators of abiotic stresses in soil: A review

With the continuous increase in human population,there is widespread usage of chemical fertilizers that are responsible for introducing abiotic stresses in agricultural crop lands.Abiotic stresses are major constraints for crop yield and global food security and therefore require an immediate response.The implementation of plant growth-promoting rhizobacteria(PGPR)into the agricultural production system can be a profitable alternative because of its efficiency in plant growth regulation and abiotic stress management.These bacteria have the potential to promote plant growth and to aid in the management of plant diseases and abiotic stresses in the soil through production of bacterial phytohormones and associated metabolites as well as through significant root morphological changes.These changes result in improved plant-water relations and nutritional status in plants and stimulate plants’defensive mechanisms to overcome unfavorable environmental conditions.Here,we describe the significance of plant-microbe interactions,highlighting the role of PGPR,bacterial phytohormones,and bacterial metabolites in relieving abiotic environmental stress in soil.Further research is necessary to gather in-depth knowledge on PGPR-associated mechanisms and plant-microbe interactions in order to pave a way for field-scale application of beneficial rhizobacteria,with the aim of building a healthy and sustainable agricultural system.Therefore,this review aims to emphasize the role of PGPR in growth promotion and management of abiotic soil stress with the goal of developing an eco-friendly and cost-effective strategy for future agricultural sustainability.     

Adventitious shoot regeneration from the leaves of some pear varieties (Pyrus spp.) grown in vitro

The pear (Pyrus spp.) is one of the most important temperate fruit crops. A complete protocol for adventitious shoot regeneration was developed from the leaves of four pear varieties grown in vitro: Abbe Fetel, Yali, Packham’s Triumph and Aikansui, and the Chinese rootstock variety Duli. Shoot explants were collected from the field and cultured in vitro in Murashige and Skoog (MS) media supplemented with 1.0 mg·L⁻¹ 6-benzylaminopurine (BA) and 0.1 mg·L⁻¹ indole-3-butyric acid (IBA). After four weeks, leaf explants of all 5 varieties grown in vitro were excised and cultured in MS media supplemented with 0.0 mg·L⁻¹, 0.2mg·L⁻¹, 0.5 mg·L⁻¹, 1.0 mg·L⁻¹ and 2.0 mg·L⁻¹ naphthaleneacetic acid (NAA) and 5.0 mg·L⁻¹ BA or with 1.0 mg·L⁻¹, 2.0 mg·L⁻¹ and 4.0 mg·L⁻¹ thidiazuron (TDZ). The cultures were maintained in darkness for 21 days for shoot induction in the shoot induction medium (IM), then transferred to the shoot expression medium (EM) in 1.0 mg·L⁻¹ TDZ without any auxins and kept in a growth room at (25±2)°C under a 16/8 h light/dark photoperiod regime for 8 weeks. Finally, the shoots were transferred to the MS shoot elongation medium (SEM) supplemented with 0.2 mg·L⁻¹ BA, 0.1 mg·L⁻¹ IBA and 0.2 mg·L⁻¹ gibberellic acid (GA₃). A combination of TDZ and NAA had a significant effect on the number of shoot regenerations in all 5 tested varieties. The maximum mean number of shoots and maximum number of shoots per leaf obtained from Yali variety were 11.8 (P⩽0.001) and 22, followed by Aikansui with 6.6 (P⩽0.001) and 4.6, and Duli with 8 (P⩽0.001) and 12, all arising from the combination of 0.2 mg·L⁻¹ NAA with 1.0 mg·L⁻¹ TDZ. For Packham’s Triumph and Abbe Fetel, the maximum mean number of shoots and maximum number of shoots per leaf were 5.6 (P⩽0.001), 4.8 and 8 (P⩽0.001), and 11, respectively, from the combination of NAA (1.0 mg·L⁻¹) and TDZ (2.0 mg·L⁻¹). Abbe Fetel was the only variety which produced significantly higher adventitious shoots from the two different combinations of 1.0 mg·L⁻¹ NAA and 5.0 mg·L⁻¹ BA (P⩽0.05), and 2.0 mg·L⁻¹ NAA and 5.0 mg·L⁻¹ BA (P⩽0.01). Some of the most prominent problems associated with shoot proliferation and regeneration were also observed and discussed in this paper.     

Comparative transcriptome analysis provides insights into the mechanism of pear dwarfing

Dwarfism is an important trait which is closely related to the efficiency of fruit orchard management and production. However, dwarfing cannot be widely applied in the cultivation of pears, especially Asian pears. Developing varieties with dwarf characteristics is a goal of paramount importance in pear breeding. In the present study, dwarf phenotype pears(DPPs) and arborescent phenotype pears(APPs) were obtained from the offspring of a cross between ‘Aiyuxiang’ and ‘Cuiguan’ pear cultivars, whic...     

不同品种玫瑰扦插技术研究

以‘珲春’、‘牟平’、‘唐红’、‘紫枝’4个玫瑰品种的插穗为试材,研究激素、基质、扦插方式等因素对其扦插成活率的影响。结果表明:利用间歇喷雾设备进行玫瑰嫩枝扦插的生根率远远高于普通硬枝扦插,生根率最高的组合是50mg/L ABT1+处理1h+蛭石;混合基质扦插的成活率高于单一基质;4个品种中‘紫枝’生根率最高。