食品上的应用

<正>采用酵母突变株NO325(被重新鉴定为雷沃特假丝酵母)使异柠檬酸生产得到改善。采用NTG诱变得到的突变株NO OM-102被选为生产酸的最好菌株。种子培养物采用含葡萄糖、琥珀酸按盐以及酵母膏的培养基制备。于30℃,振荡培养2天。将种子培养物接种到含葡萄糖、盐类、硫胺素盐     

红松阔叶林中红松种子的分布及更新

天然阔叶红松林的红松种子经过动物活动的处理,在林内呈四个层次的垂直分布．其中在地被物下是以簇状埋藏着,数量相当多,尤其在红松密林中高大树木的周围,这些簇状分布的种子成为红松天然更新的基础。在次生阔叶林中红松种子埋藏量则很小。而埋藏位置与红松幼苗适生生境的不吻合是红松天然更新的主要障碍。     

ABA-Mediated Inhibition of Germination Is Related to the Inhibition of Genes Encoding Cell-Wall Biosynthetic and Architecture： Modifying Enzymes and Structural Proteins in Medicago truncatula Embryo Axis

Radicle emergence and reserves mobilization are two distinct programmes that are thought to control germination. Both programs are influenced by abscissic acid （ABA） but how this hormone controls seed germination is still poorly known. Phenotypic and microscopic observations of the embryo axis of Medicago truncatula during germination in mitotic inhibition condition triggered by 10 μM oryzalin showed that cell division was not required to allow radicle emergence. A suppressive subtractive hybridization showed that more than 10% of up-regulated genes in the embryo axis encoded proteins related to cell-wall biosynthesis. The expression of α-expansins, pectin-esterase, xylogucan-endotransglycosidase, cellulose synthase, and extensins was monitored in the embryo axis of seeds germinated on water, constant and transitory ABA. These genes were overexpressed before completion of germination in the control and strongly inhibited by ABA. The expression was re-established in the ABA transitory-treatment after the seeds were transferred back on water and proceeded to germination. This proves these genes as contributors to the completion of germination and strengthen the idea that cell-wall loosening and remodeling in relation to cell expansion in the embryo axis is a determinant feature in germination. Our results also showed that ABA controls germination through the control of radicle emergence, namely by inhibiting cell-wall loosening and expansion.     

Preparation and preliminary application of monoclonal antibodies against Trichokirin-S1, a small ribosome-inactivating peptide from the seeds of Trichosanthes kirilowii

Trichokirin-S1,a small ribosome-inactivating peptide recently purified from the seeds ofTrichosanthes kirilowii,has potential clinical applications because of its small molecular mass.Two stablestrains of hybridomas (1F11 and 2A5) that can secrete highly specific monoclonal antibodies (mAbs) againstTrichokirin-S1 have been developed using the hybridoma technique.The isotypes of these two mAbs,1F11and 2A5,were determined to be IgG_(2a) and IgG_1,respectively.The affinity constants,which were measuredby non-competitive ELISA,were found to be 2.3×10~8 M~(-1) and 2.8×10~8 M~(-1),respectively.An immunoaffinitymethod using 2A5-coupled Sepharose 4B was successfully developed to purify Trichokirin-S1.These twoantibodies have also been used to detect Trichokirin-S1 in Western blot.     

鼎湖山针阔混交林锥栗种子距离制约研究

Janzen-Connell 距离制约假说认为:扩散到远离母树地点的种子,更容易逃避种子捕食者和病原体侵染。验证锥栗(Castanopsis chinensis)种子是否支持该假说,可以预测锥栗种群分布格局,解释锥栗种群更新不良的原因。在鼎湖山针阔混交林内,选择离成年母树3、10和15 m处,进行种子放置实验,以及种子消毒和未消毒埋土实验。在无覆盖实验中,10 m处大种子的消失数始终最大,种子离母树距离和种子大小两个因素对种子消失数均没有显著性影响。在排除哺乳动物实验中,种子放置第一周,种子消失数均很少。整个试验期,种子离母树距离和种子大小两个因素对种子消失数也没有显著性影响。在病原体实验中,埋土前两个月,经过消毒的种子袋中种子均保存完好,没有病原体侵染。埋土的种子从第三个月到第六个月,不同距离处的种子,以及消毒和未消毒处理的种子,被侵染数之间均有显著性差异;被侵染的种子数到第六个月趋于稳定。因此,锥栗种子被脊椎动物取食,不呈现距离制约(Distance-dependent)格局;而被病原体侵染的种子命运则支持距离制约假说。     

植物人工种子研究进展

本文综述了近２０年来植物人工种子研究的进展,并对人工种子的诸领域：概念、意义、动态、应用前景、体细胞胚的诱导与同步化、包埋方法、人工种皮、干化、贮藏及防腐等进行了概述。结合我们在铁皮石斛人工种子方面的研究,提出了人工种子应解决的问题及今后的研究方向。     

古莲子与现代莲子ABA含量和SOD活性的比较研究

本研究选用种龄为 580± 70年的古莲子──太子莲 ,和与之亲缘相近的种龄为 8年的现代哈尔滨莲 ,对比测定其脱落酸的含量及超氧物歧化酶活性 ,以期探讨距今已有几百年种龄的古莲仍能保持其活力、萌发、开花的现象与这两项生理指标的关系。实验结果表明 ,两种莲子的皮 (果皮和种皮 )ABA含量均很高 ,太子莲和哈尔滨莲分别为 4.1 8μg/g ,5.69μg/g。SOD活性在莲子吸胀期和幼苗期两种莲子的子叶中差异不明显 ,而在胚和幼芽中 ,太子莲比哈尔滨莲分别高出 50 %和 2 7%。基于以上结果 ,说明其胚中具有较强的抗逆性物质 ,利于保持其生命力。莲皮中高含量的ABA及胚中高活性的SOD有利于莲子的休眠和增强其抗逆性 ,并保持胚的生命力     

不同群落中四川大头茶 (Gordonia acuminata)花粉游离脯氨酸含量与种子产量

 四川大头茶(Gordonia acuminata)是缙云山亚热带常绿阔叶林的优势树种之一。对缙云山3种不同群落中四川大头茶的花粉游离脯氨酸含量和果实的种子产量进行了研究,发现花粉游离脯氨酸含量和每果种子产量在同一群落中的不同龄级四川大头茶个体间没有差异,但在不同群落间表现出差异。常绿阔叶林中的四川大头茶个体具有最高的花粉游离脯氨酸含量和每果种子产量,四川大头茶纯林中的次之,针阔混交林中的最低。分析发现,四川大头茶花粉游离脯氨酸含量与果实的种子产量有密切的正相关关系,花粉中的游离脯氨酸含量可以作为一种预测和比较相同地区不同生态环境中四川大头茶种子产量的指标。     

种子脱水耐性的成因及人工诱导

介绍了脱水伤害、形成种子脱水耐性的可能要素、脱水耐性的人工诱导及成功可能性的研究进展。     

豆科黄华属植物种子表面特征的研究

在扫描电镜下观察了豆科黄华属Thermopsis 18种植物种子的表面纹饰,发现 T．alpina,T.bar- bata,T．inflata,T．lupinoides,T. licentiana,T.smithiana和T．turkestanica的种子表面为粗网状,T californica,T.divaricarpa,T. macrophylla,T．mollis的种子表面为细网状,T.gracilis,T.montana,T. fabacea的种子表面为相对平滑型纹饰,T．alterniflora的种子表面为不规则条形,T．chinensis的种子表 面为粘膜状,T.rhombifolia的种子表面为条形及 T．viuosa的种子表面为碎屑状纹饰。结果表明黄华属的种子表面特征对属下类群的划分有一定意义,对澄清某些混乱的种有一定价值。