甘蓝型油菜花粉超低温保存及其花粉活力的研究

研究超低温方法保存油菜花粉过程中的预冻和解冻处理方式对油菜花粉的形态、大小及其活力的影响。结果表明:采用0℃(12h)→-4℃(12h)→-20℃(12h)→-80℃(12h)变温预冻处理和用-80℃(1h)→-20℃(1h)→4℃(1h)逐步解冻后对油菜花粉形态大小和活力影响最小。而经过25℃室温解冻法和42℃快速解冻法处理后油菜花粉出现破裂,破裂率分别达到7.6%和9.1%。同时液氮保存油菜花粉的时间长短对花粉的大小及活力影响不大。     

冷藏唐菖蒲切花瓶插过程中水分平衡及若干生理指标的变化

测定唐菖蒲新鲜切花和冷藏切花瓶插过程中的水分平衡、鲜重与某些生理指标的变化。结果表明,瓶插过程中,冷藏切花吸水和失水初时受阻,鲜重增加值大大低于新鲜切花;与瓶插同期的新鲜切花相比,冷藏切花各部位小花花瓣和苞片可溶性蛋白质明显降低,丙二醛(MDA)含量明显较高,过氧化物酶(POD)活性和过氧化氢酶(CAT)活性均明显下降。对唐菖蒲切花冷藏后品质变劣的原因作了讨论。     

海州常山花粉低温贮藏及其生理生化特征研究

以海州常山花粉为研究材料,探究了贮藏方式、贮藏时间、贮藏温度及预冻方式、低温解冻方式对花粉萌发率的影响,以及-80 ℃及4 ℃低温贮藏过程中海州常山花粉保护酶活性和渗透调节物质含量的变化,以筛选海州常山花粉的培养方法及贮藏条件,为其杂交育种奠定基础。结果表明：（1）进行低温贮藏时,花药和散粉两种贮藏效果差异不显著;不同的预冷方式对花粉低温贮藏影响并不显著;-80 ℃贮藏条件下,37 ℃水浴解冻效果显著优于室温解冻。（2）海州常山花粉在-80 ℃低温下贮藏90 d后仍具有7.99%的萌发率,更有效的保持了花粉萌发率。（3）随着低温胁迫时间的延续,4 ℃及-80 ℃两种低温条件下贮藏的海州常山花粉超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性均呈现出先升后降的趋势。（4）4 ℃及-80 ℃两种低温贮藏的海州常山花粉可溶性糖含量及-80 ℃低温贮藏的海州常山花粉可溶性蛋白含量,随着低温胁迫时间的延续,呈现出先升后降的趋势;4 ℃低温贮藏条件下的海州常山花粉可溶性蛋白含量呈现逐渐下降的趋势。研究认为,海州常山花粉更适宜于在-80 ℃低温下长期贮藏,它可以通过提高自身的SOD、POD活性,增加可溶性糖和可溶性蛋白累积来增强抗寒性,维持自身活力。     

桃品种'八月香'花粉的超低温保存

桃品种‘八月香’的花粉经4℃硅胶干燥8h或(20±1)℃下玻璃化液PVS4(35%甘油 20%乙二醇 0.6mol·L-1蔗糖)处理60min后直接投入液氮保存,解冻后的萌发率都可以达到70%以上,萌发率与保存时间长短无关。     

催花液对唐菖蒲切花水分生理及衰老的影响

本研究用两种不同催花液对唐菖蒲切花进行了处理。结果表明催花液不但具有催花效应,而且具有保鲜效应;催花液Ｉ的效果优于催花液Ⅱ。结果还表明催花液能够提高唐菖蒲切花的开放率（第１５天比对照平均多３４．４８％）,降低衰老率（第１５天比对照平均人低５６．８２％）,明显地缓解切花水分胁迫,改善体内水分平衡,抑制和缓解干物质和蛋白质的降解。     

超低温保存处理对水曲柳胚胎生理生化特征的影响

以合子胚作为保存材料,进一步分析超低温保存处理前后的水曲柳合子胚细胞各生理生化指标的变化情况,明确冷冻方式和脱水时间对生理生化指标的影响,为建立水曲柳优良遗传材料长期保存方法提供生理数据支撑。在脱水120 min条件下,合子胚经快冻法保存后,细胞内脱氢酶活性最高,同时过氧化氢酶活性、过氧化物酶活性、脯氨酸质量分数均达到最大值,分别为1 168.85 U·g^-1·min^-1、338.33 U·g^-1·min^-1、394.99μg·g^-1;经玻璃化法保存后,合子胚细胞内脱氢酶活性、脯氨酸含量、过氧化物酶活性、过氧化氢酶活性均为最小值;经慢冻法保存后,合子胚细胞内可溶性蛋白质量分数和超氧化物歧化酶活性均达到最大值,分别为18.82 mg·g^-1和361.97 U·g^-1,显著高于其他冷冻方法。干燥脱水120 min结合快冻法处理条件下,合子胚的活力达到最高值。研究结果表明,不同冷冻方式、不同脱水时间及二者的交互作用均会影响水曲柳合子胚的存活...     

天女木兰花粉形态特征及其生活力

对天女木兰（Magnolia sieboldii）花粉的采集时期、形态以及培养的温度和培养基进行了研究,并探讨贮存温度和时间对花粉生活力的影响。结果表明,扫描电镜观察到的花粉形状和萌发孔与其他已报道的木兰科植物相同,但大小和花粉外壁的纹理不同。在花瓣刚刚展开的初花期采集的花粉生活力最高。25℃下最适于花粉的萌发;花粉在含10％蔗糖＋0．1％硼酸的培养基上培养14h的萌发率最高,0．01％～0．05％的氯化钙对花粉的萌发影响不显著,0．1％的氯化钙对花粉的萌发有抑制作用。随着贮存时间的延长,花粉萌发率不断降低。不同贮存温度下花粉萌发率的降低速度依次为-10℃〈4℃〈25℃,-10％下贮藏5d的花粉萌发率降低了48．8％,10d后萌发率降低为0。     

花烛体细胞胚胎发生过程中相关生理生化特征研究

以花烛品种Amigo为材料,研究了悬浮培养条件下花烛体细胞胚胎发生过程中相关生理生化特征。结果表明:POD、CAT在胚性愈伤组织阶段维持较高活性,而SOD在体胚发育后期阶段活性较高;可溶性蛋白质含量在胚性愈伤组织阶段出现高峰;可溶性糖含量变化表现为先上升后下降的趋势,而淀粉含量表现为先下降后上升的趋势;SDS-PAGE电泳分析表明,胚性愈伤组织阶段蛋白质表达量高,种类多,并出现多种特异蛋白。分析认为胚性愈伤组织阶段是调控花烛体细胞胚胎发生过程的关键阶段。     

超低温冷冻对益智种子生理生化特性的影响

益智(Alpinia oxyphylla)是我国四大南药之一,其种子为顽拗性种子,不耐干燥和低温,无法常规保存。为解决益智种子长期稳定保存的问题,该研究以益智种子为材料,从种子含水量以及冷冻方式方面优化益智种子超低温保存方法,并对比液氮冷冻前后种子发芽率、α-淀粉酶活性、超氧化物歧化酶活性、过氧化物酶活性、脱氢酶活性、丙二醛含量等活力指标,分析液氮超低温冷冻对益智种子生理生化特性的影响。结果表明:直接液氮冷冻含水量13.92%~14.38%范围的种子是益智种子超低温保存的最佳条件。液氮冷冻后,随着超低温冷冻时间的延长,益智种子发芽率先由76.76%下降至52.5%,再上升至65%,最后下降并稳定在50%以上。其种子α-淀粉酶活性先下降后上升,然后又下降,最后上升并稳定至冷冻前的水平。丙二醛含量则是先上升后下降,最后趋于平稳状态。过氧化物酶活性是先下降,然后稳定在恒定水平。超氧化物歧化酶活性是随着冷冻时间的延长而持续上升,脱氢酶活性则是持续下降。以上结果说明,液氮冷冻时间对益智活力有一定的影响,但对种子有些性能具有一定的促进作用。无论是发芽率,还是生理生化指标,都不同程度表明液氮超低温保存益智种子是可行的。     

无距虾脊兰花粉离体萌发及储藏条件的研究

以天目山野生无距虾脊兰的花粉为材料,采用离体萌发法研究了花粉的储藏性以及不同的培养基组分和培养条件对花粉萌发和花粉管生长的影响,并采用联苯胺-过氧化氢法测定了其柱头的可授性,以筛选无距虾脊兰花粉的培养方法以及储藏条件,为其种质资源保存等研究奠定基础。结果表明:(1)无距虾脊兰最适花粉液体培养基为200g·L-1蔗糖+50mg·L-1 H3BO3+40mg·L-1 Ca(NO3)2·4H2O,并且在pH 5.5~6.0、温度25℃恒温下培养48h,无距虾脊兰花粉萌发率(81.71%)和花粉管生长(247.42μm)最佳。(2)无距虾脊兰花粉在-80℃中低温干燥储藏360d后仍具有48.58%的萌发率。(3)无距虾脊兰的柱头在开花前5d内均具有可授性,花粉块在整个花期内均保持了28.96%~81.71%的生活力,但柱头可授性和花粉活力均随开花后时间的延长显著降低。     

景宁木兰花粉萌发与贮藏特性研究

以景宁木兰的花粉为试材,采用花粉离体培养法,用单因子与正交试验研究不同浓度蔗糖、H3BO3、CaCl2所组成的基本培养基对景宁木兰花粉萌发的影响,同时探讨不同贮藏条件和贮藏时间对花粉活力的影响。结果表明:景宁木兰在30 g·L-1蔗糖+200 mg·L-1H3BO3+200 mg·L-1CaCl2的液体培养基上萌发率最高(74.56%)。低温条件下有利于景宁木兰花粉生活力的保持,在-80℃条件下,花粉生活力下降较慢,并且随着贮藏时间的增加,经过硅胶干燥的花粉的活力明显高于湿润花粉的活力。     

Fluorescence Microscopic Observations on Actin Filament Distribution in Corn Pollen and Gladiolus Pollen Protoplasts

Actin filament (AF) distribution in Zea mays pollen and Gladiolus gandavensis pollen protoplasts was localized by FITC conjugated phalloidin fluorescence microprobe. The pollen was incubated in Brewbaker and Kwack (BK) medium, and the pollen protoplasts were isolated enzymatically and cultured in K3 medium containing various supplements by a previously reported method. Samples were fixed for 30 min with 1.5% paraformaldehyde dissolved in 0.1 mol/1 phosphate buffer (pH 7), half strength of BK elements, 1 mol/1 EGTA and sucrose, stained for 30–60 min with 1 μg/ml FITC-phalloidin in the buffer solution, and observed by a fluorescence microscopy. In hydrated corn pollen grains, the AFs constituted an irregular network. Prior to germination a part of the pollen grains showed polarized pattern of Afs. At the opposite pole to the germ pore, there was a center from which AF bundles radiated and converged toward the pore, often making a spindle-shaped configuration. In just isolated gladiolus pollen protoplasts, the AFs appeared as irregular fine network. After 4–7h of culture, the AF distribution coincided in some cases with the unevenly regenerated new wall area as exhibited by FITC-phalloidin and Calcofluor White ST double staining, indicating a possible involvement of AF in wall synthesis. After 17–18 h of culture, a part of the pollen protoplasts went on germination. The AFs became polarized in such protoplasts and converged into the tubes produced, and ran longitudinally along the tubes just like in the tubes germinated from pollen grains. However, in ungerminated pollen protoplasts, the AFs behaved abnormalty, showing various irregular arrangements. When protoplasts bursted, the actin aggregates often located at the protrusion site from which the protoplasts would burst, and were discharged into the medium. In neither corn pollen nor gladiolus pollen protoplasts AFs were observed within the generative or sperm cells.     

Resource allocation to growth,reproduction and survival in Gladiolus : The cost of male function

Theoretical models of life-history evolution assume trade-offs between present and future reproduction and/or survival. Models of the evolution of sex assume trade-offs between male function and female function. Generally, experiments designed to evaluate the cost of reproduction on other functions tend to ignore male function. The present work on Gladiolus takes into account simultaneously the different primary functions of the plant and separates sexual reproduction into one male component (pollen production) and one female component (seed production). The study of environmental (within-clone), between-clone and genetic correlations using strains of Gladiolus and principal component analysis show that trade-offs exist between male function, female function and survival, including both characters of plant vigour, perennation (corm production) and vegetative propagation (cormel production). Phenotypic correlations, using different species and species-hybrids, have been obtained which confirm these results. In particular, these results underline the importance of the impact of pollen production on the other functions.     

An Ultrastructural Study on Pollen Protoplasts and Pollen Tubes Germinated From Them in Gladiolus gandavensis

Large quantities of protoplasts were isolated enzymatically from the mature pollen grains in Gladiolus gandavensis. Regeneration of cell wall and germination of pollen tubes were performed during culture of purified pollen protoplasts in Ks medium supplemented with 32% sucrose, 0.1 mg/1 2,4-D, 1 mg/1 NAA and 0.2 mg/1 6-BA, with a germination rate up to 47.7%. The materials were fixed gently with gradually increasing concentration of glutaraldehyde, followed by osmium, then preembedded in a thin layer of agar and surveyed under an inverted microscope so as to select desired specimens for subsequent procedure. Small agar blocks containing specimens were dehydrated through ethanal-propylene oxide series, embedded in Araldite and ultratomed. Electron microscopic observations show that the pollen protoplasts are surrounded by a smooth plasma membrane and with ultrastructurally intact cytoplasm, a vegetative nucleus and a generative cell. After 8h of culture, wall regeneration commences resulting in a multilayered, fibrillar wall structure which is different from the intine. No exine is formed. Numerous vesicles participate actively in the wall formation. The wall is uneven in thickness around its periphery; a thickened area somewhat resembling to germ furrow is formed, from which pollen tube emerges. The tubes contain abundant plastids, mitochondria and dictyosomes. Vesicles are released out of the plasma membrane and involved in tube wall formation. After 18h of culture, the vegetative nucleus and generative cell have migrated into the tube. Technical points of preparing pollen protoplast specimens for ultastructural studies and the fearnres of wall regeneration in pollen protoplast culture are discussed.     

玉米花粉的冷藏研究

本研究的目的是寻找一种可行的花粉贮藏方法。我们采用快速冷冻－真空干燥－常低温保存的方法进行花粉贮藏研究。对贮藏花粉分别作了活性染色,过氧化物酶同工酶活性分析及花粉培养,以测定其生活力（以下称活力）。研究表明,快速冷冻－真空干燥－常低温（－１０℃─－２０℃）保存玉米花粉的方法是可行的。保存１５０天的玉米花粉仍有８％的萌发率。同时证明,常用的各种染色方法只能反映花粉的成熟度,而不能作为检验花粉是否具有活力的唯一标准。而花粉是否能够萌发,即长出正常的花粉管,才是判断花粉活力的主要指标。     

大花红山茶花粉形态特征和培养条件及其储藏过程的生理动态分析

以大花红山茶花粉为材料,用扫描电子显微镜观察花粉表观形态,采用离体培养法研究花粉的萌发特性,并就不同贮藏温度与时间对花粉萌发率、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响进行了分析。结果表明:(1)大花红山茶花粉极面观呈正三角形,沟界极区较宽;花粉粒纹饰为穴状、小沟状雕饰纹;花粉粒平均极轴长为71.05μm;说明大花红山茶在山茶属中具有较为特殊的分类地位和系统进化地位。(2)大花红山茶花粉萌发的最适宜培养基为:150g·L-1蔗糖+20mg·L-1硼酸+100mg·L-1 KNO3+50mg·L-1MgSO4+300mg·L-1 Ca(NO3)2,花粉萌发率可达68.10%。(3)大花红山茶花粉最佳贮藏条件为-80℃;-80℃下贮藏360d后,萌发率仍可达到39.40%。(4)-20℃、-80℃贮藏条件下,大花红山茶花粉3种保护酶(SOD、POD、CAT)的活性较高,花粉抗氧化、抗衰老的能力较强;且在花粉贮藏过程中,3种酶活性高峰值前后花粉萌发率出现大幅度下降。(5)不同贮藏温度下,3种保护酶的作用不同,常温下,SOD为敏感性保护酶;4℃、-20℃下,POD为敏感性保护酶;-80℃下CAT为敏感性保护酶;3种酶活性对花粉萌发率的影响依次为:过氧化氢酶超氧化物歧化酶过氧化物酶。     

1-MCP对‘粉红女士’苹果冷藏期间品质变化和香气形成的影响

以'粉红女士'苹果为试验材料,研究了1 μL/L 1-MCP(1-甲基环丙烯)对苹果冷藏期间乙烯释放速率、呼吸速率、果实硬度以及香气成分和相对含量的影响.结果表明,1-MCP处理可显著抑制'粉红女士'苹果冷藏期间呼吸作用和乙烯释放,有效延缓果实硬度的下降.冷藏期内'粉红女士'苹果香气物质主要有醇类、醛类、酯类、烯类、酸类和烷烃类等,并以酯类香气为主(占46.15%);1-MCP能显著减少果实贮藏期间酯类、醇类和烷烃类香气成分种类和相对含量,处理果中酯类和醇类香气成分种类比同期对照分别减少了50%和78%,主要香气成分丁酸己酯在处理和对照果实的相对含量分别为1.12%～1.73%和1.87%～5.18%.可见,1-MCP处理对'粉红女士'苹果具有良好保鲜效果,也显著地抑制了贮藏期间香气的形成.