V_B对番茄根尖离体培养的效应

用番茄的离体根尖作为外植体 ,在MS培养基上添加不同质量浓度的VB1 、VB6 及二者组合。结果表明 :硫胺素 (VB1 )是必须的 ,缺乏它根的生长受阻 ,所用质量浓度在 0 .1～ 1.0mg/L ,其对生长的促进作用与所用质量浓度成正比 ;吡哆醇 (VB6 )的作用也是明显的 ,它与硫胺素共同作用 。

籼稻9311成熟胚再生体系

建立9311水稻高效再生体系,将有利于人们以9311水稻为受体进行遗传改良及籼型水稻基因功能的研究.报道了9311成熟胚高效再生途径.以9311成熟胚为外植体,设计了5类(N_6DP,N_6DA,MSDP,MSDA和MSDAP)共13种不同愈伤组织诱导培养基,比较了9311成熟胚在不同培养基中愈伤组织的诱导以及初始愈伤组织被继代后的表现.结果显示:9311成熟胚在添加2,4-二氯苯氧乙酸(2,4-D)的所有培养基中都能够形成愈伤组织;将最初被诱导的愈伤组织进行继代培养,在前4类培养基上诱导的初始愈伤组织,不论被分别继代于与原培养基成分相同的新鲜培养基上,还是被继代于MSDAP培养基上,继代后的愈伤组织都相继褐化死亡,而将从MSDAP培养基上诱导的初始愈伤组织继代在MSDAP培养基上,愈伤组织很少出现褐化现象,并且能够较快地增殖.由此表明,MSDAP培养基是9311成熟胚合适的愈伤组织诱导培养基和增殖培养基.采用MSDAP培养基培养,9311水稻成熟胚愈伤组织诱导率达87.5%,分化率为46.7%,再生植株的比例为23.3%.

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.

Effect of Different Treatment on Anther Callus Formation and Browning in Balsam Pear （Mornordica charantia L.）

Brown callus derived from anther limited the application of anther culture in balsam pear. In order to establish a more perfect regeneration system from anther cultuer, the effects of low temperature pretreatment, 2,4-dichlorophenoxyacetic acid （2,4-D）, vitamin C （Vc） and silver nitrate （AgNO3） on callus induction and browning in anther culture of balsam pear （Momordiea charantia L.） were investigated. The results showed that after pretreatment at 4 ℃ for 1 day, callus induction rate was the highest and browning rate was the lowest. Anthers on MS medium supplemented with 2,4-D 0.5 mg/L formed more and better callus. The medium supplemented with Vc or AgNO3 was advantageous to the induction of callus and reduction of browning. When cultured on medium supplemented with 50 mg/L Vc or 5 mg/L AgNO3, callus induction rate was the highest and browning rate was rather low.

Effect of Growing Conditions of Rice Donor Plants on Anther Culture in Vitro

An experiment was conducted to find the effect of three types of donor plants growing conditions （growth chamber, open space ＋ growth chambers and open space） on callus induction and subsequent plant regeneration and productive shoot regeneration from the anthers culture in vitro of four rice hybrid （1-2, 2-1, 7-1, 13-3） developed by Primorsky Scientific Research Institute of Agriculture. Five variants of N6 medium （N6-I, N6-2, N6-3, Mix-l, N6-4） were used as basal medium. Mean value of callus induction frequency on three types of conditions ranged from 5.68% to 9.44% and the difference was non-significantly. In general, callus derived from donor plants grown on condition of open space ＋ growth chambers showed significantly better performances for plant regeneration （0.23 green regenerants on anther and 3.77 green regenerants on callus） and productive shoot regeneration （0.06 productive regenerants on anther and 0.56 productive regenerants on callus）. Favourable conditions for donor plant growth in open space positively affect on callus induction and regenaration. It is possible to get assured results on many hybrids, but not the highest. In growth chamber, frequency of callus induction can be the maximal only on some samples, few hybrids are resulted in deficiency of callus induction.

Preliminary Investigation on Somatic Embryogenesis from Immature Cotyledon Explants of Shea （Vitellaria paradoxa G,）

Long juvenile phase and lack of effective protocols for large scale vegetative propagation are limitations to domestication and improvement of the shea tree. The present study seeks to develop a protocol for plant regeneration of shea （Vitellaria paradoxa） from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium （MS） containing 3% sucrose, 0.24% Phytagel, and various concentrations of 2,4-Dichlorophenoxyacetic acid （2,4-D） after four weeks of culture in darkness. Rates of embryogenic callus induction were significantly affected by the addition of 2, 4-D to the medium. Within 28 days of culture, the highest percentage of embyogenic calli （77.61%） occurred on MS media containing 0.45 ~tM of 2,4-D in the dark. Somatic embryos were obtained by culturing embryogenic callus （in the dark） on MS medium fortified with 3% sucrose, 0.24% phytagel and devoid of growth regulators. Culturing at 16 h photoperiod restricted both the induction of embryogenic calli cultures and somatic embryos. Somatic embryos germinated, developed shoots and rooted vigorously on MS medium devoid of growth regulators. Germinated plantlets were acclimatized, successfully.

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.