兰州百合继代培养过程中的染色体变异

对兰州百合 (Liliundavidiivar Unicolor(hong)cotton)组培过程中的染色体行为进行了研究 .随着其继代次数的增加 ,愈伤组织细胞染色体数目变异随之增加 .而继代次数对诱导小鳞芽的染色体数目影响不大 ,仅与诱导成芽率成负相关 .

水稻耐冷性研究 Ⅰ.稻冷害类型及耐冷性鉴定评价方法概述

本文是水稻耐冷性研究的第一部分 ,介绍水稻冷害的类型及耐冷性鉴定评价方法。水稻的冷害类型可以分为延迟型冷害和障碍型冷害 ;也可以按照低温冷害发生的时期来划分成芽期冷害、苗期冷害、孕穗期冷害、开花期冷害和灌浆期冷害。较系统地介绍了水稻芽期、苗期、孕穗期、开花期耐冷性的多种鉴定评价方法及其评价指标和自然条件下的耐冷性鉴定方法。

两步外植体法高频再生麝香百合(英文)

采用两步外植体法,即以百合鳞片叶为初始外植体,以从初始外植体上长出的芽为次级外植体,成功建立了麝香百合的高频离体再生系统。对不同的BA浓度及次级外植体的不同部位对再生效果的影响,以及组培苗移栽前低温处理的影响进行了研究。结果表明:不同部位的次级外植体中,以短缩茎切片出芽快、整齐、芽数多且粗壮;以MS附加1.0 mg L-1 BA和0.1 mg L-1 NAA的培养基最适于麝香百合的分化。一个中等大小已脱春化的鳞茎通过两步外植体法能扩繁出54 000株左右的新植株,从鳞片叶开始至开花仅需8个月,而且4!低温处理对开花期的影响不大。

包埋玻璃化法超低温保存植物种质的研究进展

包埋玻璃化法是在玻璃化法和包埋脱水法基础上发展起来的超低温保存植物种质的新技术。它具有能同时处理大量材料,处理后恢复生长快,对材料的毒害作用较小及成芽率高等优点,已成功地用于辣根、山嵛菜等20余种植物,在植物种质资源的保存上显示出了巨大的应用潜力。本文介绍了包埋玻璃化法产生的背景及其优点,阐述了包埋玻璃化法的基本方法和预培养、包埋、脱水、化冻及恢复培养等过程,比较了该法冻存后的效果和冻存后所形成植株的遗传稳定性,同时指出了进一步研究的重点。

植物生长调节剂对欧李离体培养的影响

以MS为基本培养基,附加不同质量浓度的细胞分裂素BA(6-卞基腺嘌呤)、KT(激动素)和生长素NAA(萘乙酸)、IBA(吲哚丁酸),进行欧李萌芽、成芽、幼芽增殖及生根(1/2MS),形成完整的植株,从中筛选其最适宜的培养基。幼芽诱导时,以单独使用质量浓度为2.0 mg.L-1的BA最好,诱导率为100%;但混合使用时,以MS+BA 1.0 mg.L-1+NAA 0.3 mg.L-1效果最好,诱导率也为100%。欧李幼芽增殖时,则以MS+BA 1.0 mg.L-1+NAA 0.1 mg.L-1效果最好,增殖系数为8.19。生根时,以1/2MS+IBA 1.0 mg.L-1最好,其生根率为91.7%。移栽时,根长度约1.2 cm为适宜,移栽基质以蛭石为最好。

二步倍增东方百合“星球战士”及提高组培苗移栽成活率的研究(英文)

采用二步倍增法直接再生了东方百合"星球战士"。鳞片切块培养在MS+4.4μmol/L BA+ 0.5μmol/LNAA的培养基上50 d后,再生出大量丛生芽。将丛生芽切块置于同样的培养基上进行诱导,40 d后,从基部短缩茎切片上诱导出了大量不定芽,但是根切段上不再生芽。一个中等大小的东方百合"星球战士"鳞茎120 d就可以再生出97 200个独立完整的新植株。研究还发现:加椰糠的培养基质最适于组培苗的驯化培养因而获得最高的移栽成活率。组培苗移栽后生长正常,2 a后正常开花。

马来甜龙竹组培快繁技术研究

本文报导了马来甜龙竹组培快繁的研究结果。试验表明,试管苗茎段在MS+BA4 0mg/L的培养基上离体培养,能诱导产生丛生芽,继代周期以45d为佳,增殖倍数可达3 2;茎段平放较插放的效果好;试管苗在1/2MS0培养基上,生根率达90%;按常规方法移栽到沙混表土(1∶1)上较易成活。

植物生长调节剂对含笑离体培养的影响

以1/2MS为基本培养基,研究了不同浓度的细胞分裂素和生长素,对含笑茎段萌芽、成芽、幼芽增殖及生根诱导的效果。结果表明:细胞分裂素单独使用时,低浓度BA(0.5～1.0mg·L-1)有利于成芽的诱导,诱导率均为100%。ZT(1.0～4.0mg·L-1)能诱导腋芽萌动,萌芽率为100%,细胞分裂素(BA、ZT)和生长素(IAA)混合使用时ZT2.0mg·L-1+IAA0.1mg·L-1组配方式最佳,萌芽率、成芽率均为100%,增殖系数为3.50。BA1.0mg·L-1+IAA0.1mg·L-1的效果为次之。生根培养基1/2MS+IBA3.0mg·L-1最好;若附加0.1%活性炭,能提前42d发根。

Effect of ^(12)C^(6+) Ions Beam Irradiation on Seed Germination and Enzymes Activity in Seedlings of Sweet Sorghum

[ Objective] The aim was to study the effect of 12C6 ＋ ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretical foundation for sweet sorghum breeding. [ Method] After germination, the germination potential, germination fraction and enzyme activity were detected, respectively. [ Result] The results showed that with the dose increased, the germination potential of sweet sorghum increased first and then decreased, while their germination fraction presented ＂shoulder like shape＂ ; the activity of LDH, SOD, CAT and GSH-Px increased first and then decreased with doses, they presented slight differences among different enzymes. [ Conclusion] Low dose radiation could accelerate germination of sweet sorghum seeds and enzyme activity could remain at a relatively high level. Enzyme activity decreased with high doses and the growth of sweet sorghum was inhibited.

Study on Improvement of Walnut Bud Grafting Technology in the North

[Objective] This study was conducted to change the situation of high cost in walnut grafting by reducing seedling cost through technical means.[Method] Effects of different rootstock processing methods and rootstock pruning time on walnut growth and cost were studied by the square bud grafting method.[Result] The survival rate and cost under stumping were higher than those under no stumping,and the proportion of grafting-capable rootstocks under stumping was lower than that under no stumping by 9%.The cost differences between different rootstock time were remarkable.The cost for the stock pruning 15 d after grafting was 5 times as much as 1 d after grafting.[Conclusion] Direct grafting could achieve the effect of easy and convenient management,and the overall cost was lower though the survival rate was reduced to a limited extent.Sooner rootstock pruning resulted in a better effect.Pruning the rootstocks within 5 d after grafting not only could improve the quality of seedlings,but also could reduce the cost for seedling management.

The Chlorophyll Biosynthesis in Lotus Embryo Is Light-dependent

Angiosperms need light to synthesize chlorophyll, but lotus (Nelumbo nucifera Gaertn.) embryo was suspected to have the ability to form chlorophyll in the dark because lotus embryo can turn into green under the coverage of four layers of integuments (cotyledon, seed coat, pericarp, lotus pod) which were thought impossible for light to pass through. The authors excluded this possibility based on two experimental results: First, enclosing the young lotus pod with aluminium foil, the growth of louts embryo continued, but the chlorophyll formation was seriously inhibited. A lot of protochlorophyllide, chlorophyll precursor, were accumulated, most of which were combined with LPOR (light dependent protochlorophyllide oxidoreductase). Second, DPOR (dark or light-independent protochlorophyllide oxidoreductase) was the enzyme necessary for chlorophyll synthesis in the dark. The genes encoding DPOR were conservative in many species, but no homologues could be found in lotus genome. Taken together, authers' results clearly demonstrated that lotus embryo synthesizes chlorophyll only through the light-dependent pathway.

小麦种子包衣十注意

小麦种子包衣后，可提高种子发芽率和成芽率，促进幼苗发育。包衣剂中的植物生长调节剂，还可以满足小麦种子发芽生长所需养分，促进幼苗早发和苗齐苗壮，根系发达，叶色浓绿，分蘖力强。现将小麦种子包衣过程中的十项注意介绍如下。

小麦种子包衣十注意

小麦种子包衣后，可提高种子发芽率和成芽率，促进幼苗发育。包衣剂中的植物生长调节剂，还可以满足小麦种子发芽生长所需养分，促进幼苗早发和苗齐苗壮，根系发达，叶色浓绿，分蘖力强。现将小麦种子包农过程中的注意事项介绍如下：

Effect of Seed-coating Agents on Rice Seeds with Dehiscent Glumes

In order to improve the utilization efficiency of hybrid rice seeds, the effects of seed-coating agents on hybrid rice seeds with dehiscent glumes were investigated. Total six kinds of seed-coating agents were selected, i.e., 20.5% imidacloprid ·prochloraz FS, 30.5% imidacloprid oprochloraz FS, 23.0% thiamethoxam · hymexazol·prochloraz FS, Ruisheng WS, Shileshi FS and Liangdun FS, and their effects of seeds of Longliangyou Huazhan and T You 272 were investigated. The results showed that when the percentage of glume-dehiscent seeds reached 10%, 20.5% imidacloprid .prochloraz significantly improved the germination rate of Longliangyou Huazhan, which was 4.33% higher than that in the control group, and the seedling rate of Longliangyou Huazhan remained unchanged; 30.5% imidacloprid. prochloraz did not improved the germination rate of T You 272, but improved its seedling rate, which was 7.66% higher than that in the control group. When the percentage of glume-dehiscent seeds reached 20%, 20.5% imidacloprid ·prochloraz and 30.5% imidacloprid.prochloraz improved the germination rate of T You 272 by 3.50% and 4.83%, respectively, and its seedling rate did not decline. In conclusion, seed-coating agents have certain repair effect on glume-dehiscent rice seeds; 20.5% imidacloprid ·prochloraz and 30.5% imidacloprid ·prochloraz could improve the efficiency of Longliangyou Huazhan and T You 272 with small amounts of glume-dehiscent seeds.

Effect of Germination of Camellia oleifera Bud-Stock Grafting Induced with Various Hormones

[Objective] This study aimed to investigate the effect of growth regulators on the camellia （Camellia oleifera） bud stock cutting and to improve its survival rate by culturing thick and strong plumule. [Method] The effects of the different growth regulators 911 rooting agent, GA3 , ABT rooting powder on the germination ratio, the average germinating speed, the diameter of plumule and the survival rate of grafting shoots of camellia were compared and analyzed. [Result] The three growth regulators could significantly improve the growth potential of the plumules. The germination rate, plumule stem and survival rates of grafted plumules treated by the three growth regulators were much better than that of control. The germinating of camellia seeds treated with 911 rooting agent, GA3 or ABT rooting powder was 5, 7 or 9 d earlier than control; the diameter of embryo was 45%, 40% or 50% larger and the survival rate was 8%, 12% or 9% higher than that of control respectively. [Conclusion] The three hormones promoted the germination, the development of the roots including the lateral root and the fibrous, and improved the survival rate of cuttings. Among them, GA3 treatment produced the best efficiency.

Allelopathic effects of Lantana camara on germination and growth behavior of some agricultural crops in Bangladesh

An experiment was conducted to understand the growth inhibitory effects of aqueous extracts derived from Lantana camara L. （a globally recognized invasive alien weed） on six popular agricultural crops of Bangladesh. The test was conducted in sterilized petridishes with a photoperiod of 24 hours and an average temperature of 29℃. The effect of different concentrations ofL. camara leaf extracts were recorded and compared with control （i.e., distil water）. Result showed different concentrations of aqueous leaf extracts caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor crops. Bioassays also indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration had the stronger inhibitory effect whereas the lower concentration showed stimulatory effect in some cases. The inhibitory effect was much pronounced in root and lateral root development rather than shoot and germination.

Foliar modifications induced by inhibition of polar transport of auxin

The effects of auxin polar transport inhibitors, 9-hydroxy-fluorene-9-carboxylic acid (HFCA); 2, 3, 5-triiodobenzoic acid (TIBA) and trans-cinnamic acid (CA)on leaf pattern formation were investigated with shoots formed from cultured leaf explants of tobacco and cultured pedicel explants of Orychophragmus violaceus, and the seedlings of tobacco and Brassica chinensis. Although the effective concentration varies with the inhibitors used, all of the inhibitors induced the formation of trumpet-shaped and/or fused leaves. The frequency of trumpet-shaped leaf formation was related to the concentration of inhibitors in the medium.Histological observation of tobacco seedlings showed that there was only one main vascular bundle and several minor vascular bundles in normal leaves of the control, but there were several vascular bundles of more or less the same size in the trumpet-shaped leaves of treated ones.These results indicated that auxin polar transport played an important role on bilateral symmetry of leaf growth.

Callus and Adventitious Buds Formation from Stem Explants of Balsam Pear （Momordica charantia L.）

The effects of sterilization pretreatment, sampling time and growth regulators on callus formation, explant contamination and adventitious bud induction from stems of balsam pear （Momordica charantia L.） were investigated. Sterilized for 6 rain with 0.1% （w/v） mercuric chloride solution is an essential sterilization method for stems. June and July proved to be better for material taking, followed by May. The callus formation rate of balsam pears reached the highest when medium added with IBA 1.0mg/L and BA 2.0 mg/L, while the optimum medium for adventitious bud induction was MS added with IBA 0.5mg/L and BA 4.0 mg/L. And it will provide theoretical and technical basis for rapid propagation and breeding.

Changes in biochemical constituents and induction of early sprouting by triadimefon treatment in white yam(Dioscorea rotundata Poir.) tubers during storage

The ability of triadimefon （TDM）, a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam （Dioscorea rotundata Poir.） tubers during storage under （30±2） ℃ in the dark, was studied. TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10, 25 and 40 d after storage （DAS）. Starch, sugars, protein, amino acid contents as well as protease and a-amylase activities were estimated on 15, 30 and 45 DAS from two physiological regions viz., apical and basal regions of the tubers. In normal conditions （control） sprouting occurred on 70 to 80 DAS. The starch content decreased, while protein, amino acid, sugar contents and protease and a-amylase activities were increased due to TDM treatment and led to early sprouting.

Long-term natural history of Crohn’s disease

Crohn’s disease is a chronic inflammatory granulomatous process that usually involves different sites in the intestinal tract. Genetic and environmental factors are thought to play a role in its etiology and pathogenesis. The disorder has a heterogeneous clinical expression and data from tertiary care settings have documented its female predominance, occasional familial nature, and high rate of stricture formation and penetrating disease. It may appear from early childhood to late adulthood, although over 80% are currently diagnosed before age 40 years, usually with terminal ileal and colonic involvement. Several studies have now shown differences in phenotypic clinical expression depending on the initial age at diagnosis, with pediatric-onset disease being more severe and more extensive with more involvement of the upper gastrointestinal tract compared to adult-onset disease. In addition, long- term studies from these tertiary care settings have documented that the disorder may evolve with time into a more complex disease with stricture formation and penetrating disease complications (i.e. fistula and abscess). Although prolonged remission with no evidence of inflammatory disease may occur, discrete periods of symptomatic and active granulomatous inflammatory disease may re-appear over many decades. Long-term studies on the natural history have also suggested that discrete events (or agents) may precipitate this granulomatous inflammatory process.