墨兰组织培养植株的叶结构和生理特性

墨兰叶肉没有海绵组织和栅栏组织的分化 ,但在叶的不同部分的叶脉附近叶肉细胞有不同的形态变化 .叶尖和叶中部中脉附近的叶肉细胞排列紧密 ,细胞明显伸长 ,似栅栏组织 ,叶基部中脉附近的叶肉细胞没有伸长 .叶尖部叶绿体周径大 ,叶绿素含量高 ,光合速率亦较高 ,且Fv Fm、PSⅡ和qp

Callus Induction and Plant Regeneration from Mature Seeds of Perennial Ryegrass

Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.

Callus induction from leaves of different paulownia species and its plantlet regeneration

The experiment was carried out on five different species of Paulownia for callus induction from leaves. MS medium was adopted as basic medium, and from different combinations of NAA and BA the suitable media were determined for callus induction, bud differentiation, and root differentiation of five different species. MS+0.5NAA+4BA, MS+0.3NAA+2BA, MS+0.5NAA+4BA, MS+0.3NAA+6BA, and MS+0.3NAA+8BA were suitable media of callus inductions of leaves, respectively, for Paulownia tomentosa, Paulownia australis, Paulownia fortunei, Paulownia elongata and P. tmentosa x P. fortunei, and MS+0.3NAA+12BA, MS+0.3NAA+12BA, MS+0.5NAA+12BA, MS+0.5NAA+12BA, and MS+0.7NAA+12BA were suitable media for bud differentiation from leaf callus respectively for above five species. The rooting media was determined as 2MS+0.1NAA, 1/2MS+0.1NAA, 1/2MS, 1/2MS+0.3NAA, and 1/2MS+0.5NAA. These results provide reference data for breeding new fine va-rieties with different kinds of Paulownia protoplasts fusions.

Establishment of Plant Regeneration System from Immature Embryos of Maize(Zea mays L.) Inbred Lines

[Objective] The aim was to explore the conditions of high frequency induction of embryonic callus and plant regeneration of maize. [Method] Immature embryos of maize inbred lines were used as explants to study the effect of different 2,4-D concentrations on the induction of callus,the effect of different 6-BA concentrations on the differentiation of test-tube plantlet,as well as the effect of different IBA concentrations on the rooting of test-tube plantlet. [Result] 2,4-D showed obvious effect on the induction of inducement rate of maize,and the optimum induction medium was：N6 ＋ 2 mg/L of 2,4-D ＋ 500 mg/L of CH ＋ 500 mg/L of Pro ＋10 mg/L of AgNO3; the optimum differentiation medium was：N6 ＋ 0.5 mg/L of BA ＋ 500 mg/L of Pro; the optimum for the rooting of test-tube plantlet was 1/2 MS ＋ 0.5 mg/L of IBA. [Conclusion] The study had provided basis for the genetic transformation of maize.

Optimization of plant regeneration system in vitro culture in wheat

Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regeneration frequency than Piclorm, with an average frequency of 54% in all treatments. Optimal condition for different genotypic rice was as following: induction medium (MSS 3AA/2) with 0.5 mg L-1 2,4-D, regeneration medium (R) with 0.01 mg L-1 2,4-D and 3 mg L-1 KT. The average regeneration frequency reached 83.3% under the condition. Correlation analysis showed that root differentiation, in different level, correlated with green spot regeneration, and with the number of regenerated plants per callus. No correlation was found between green spots regenerated and the numbers of plants regenerated per callus.

试管苗玻璃化现象的研究进展

玻璃化是植物组织培养过程中特有的一种生理失调或生理病变,普遍发生于多种植物中。玻璃化试管苗呈透明或半透明的水浸状,叶片卷曲畸形,分化及存活能力低,无法进行继代培养及驯化移栽,给种苗商业化生产造成了严重的经济损失,也限制了组织培养技术在种质资源保存及基因工程育种中的应用。目前,对玻璃化发生的机制尚没有统一的认识。本文对玻璃化现象、发生机制以及预防措施等相关研究进行了综述,以期为研究玻璃化发生发展的机制并开发有效的防控措施提供借鉴。

Direct Adventitious Bud Induction and Plant Regeneration of Rosa hybrida Samantha

Effect of explant, site of leaflet, induction period in the dark and combinations of plant growth regulators on direct adventitious bud induction and plant regeneration of Rosa hybrida Samantha was investigated. The results showed that after an induction period of 8 d on MS medium with 1.5 mg L-1 TDZ and 0.05 mg L-1 NAA in the dark and a subculture on MS medium with 0.5 mg L-1 BA and 0.01 mg L-1 NAA under light, the best plant regeneration was obtained and the regeneration frequencies of leaflets and petioles were 51.8 and 10% respectively. There was no significant difference in regeneration ability between leaflets at different sites of the compound leaves, longer time of induction in the dark or high concentration of auxin would cause callus formation, which was disadvantageous for shoot regeneration, and the regeneration frequency was significantly reduced. This regeneration system could be applied for genetic transformation of this cultivar in the future.

Effect of Different Hormone Combinations on Somatic Embryogenesis in Cotton Cultivar Xinluzao 33(Gossypium hirsutum L.)

[Objective] This study was conducted to evaluate the efficiency of somatic embryogenesis and plant regeneration for an upland cotton cultivar Xinluzao33 under the induction of different hormone combinations and thus to determine the optimal hormone combination. [Method] Calli of Xinluzao33(Gossypium hirsutum L.) were induced from seedling hypocotyl tissue by a range of DK and BK combinations. Embryogenic calli and embryos were induced on callus-inducing medium(CIM) without any hormones. Callus appearance and quality were compared to determine which medium was the optimal for callus induction. Embryogenesis ratio was calculated to determine which medium was the best for somatic embryogenesis and plant regeneration. [Result] Callus induction rate was 100% in all the 12 hormone combinations.The calli were yellow or kelly, and their texture was loose or soft under low concentrations of DK combinations, green or white, variably compact under high concentrations of DK combinations. The calli induced by BK combinations were kelly or green, covering creamy white substance. The best medium for callus induction was DK6(0.05 mg/L 2, 4-D and 0.10 mg/L KT). Embryogenic calli were successfully induced from all the combinations. The efficiency of embryogenic callus induction,embryogenesis, and plantlet regeneration were significantly different among the 12 combinations. The result showed that the embryogenesis ratio was the highest in BK3 combination(0.50 mg/L IBA and 0.50 mg/L KT), 72.86% of embryogenic calli differentiated into somatic embryos after being cultured on CIM for 80 d, and80.93% of the somatic embryos finally regenerated into plants on SEM(somatic embryo induction medium). [Conclusion] These results indicate that hormone combination BK3(0.50 mg/LIBA and 0.50 mg/L KT) was the best medium for somatic embryogenesis and plant regeneration from Xinluzao33.