肉豆蔻种子超低温保存技术及生理生化活性研究

［目的］研究旨在探索肉豆蔻种子超低温保存方法,并检测超低温保存对肉豆蔻种子生理生化指标的影响。［方法］ 以肉豆蔻新鲜种子为材料,分别用玻璃化法、缓慢冷冻法和直接冷冻法进行超低温保存,并测定超低温保存后生活力,对生活力最高的一组超低温保存方法保存的肉豆蔻种子进行生理生化活性测定。［结果］试验结果显示,肉豆蔻种子含水量在24.44%时,用玻璃化冷冻法和缓慢冷冻法进行超低温保存生活力分别为50.00%和46.05%,且随着含水量的增加而减少。用直接冷冻法进行超低温保存时,肉豆蔻种子生活力随着含水量的增加先增加后减少,其中含水量为27.15%时,生活力最高为62.68%。直接冷冻法超低温保存前后肉豆蔻种子浸出液电导率、超氧化物歧化酶活性和过氧化氢酶活性差异不显著,丙二醛含量降低,过氧化物酶活性和α-淀粉酶活性增高。［结论］试验表明,用液氮进行超低温保存肉豆蔻的种子是可行的。     

人参裂口种子超低温保存技术研究

[目的]为人参裂口种子的长期保存建立一套技术体系。[方法]通过测定超低温保存前后裂口人参种子的生活力、发芽势、发芽率及出苗率来探究含水量及解冻方式对其超低温保存的影响;利用SSR分子标记及田间生长指标调查来鉴定超低温保存材料的遗传稳定性。[结果]含水量控制在4%~10%时,经超低温保存后的裂口人参种子仍保持较高的活力,含水量高于10%或低于4%时,活力显著下降,含水量高于30%时,种子全部失活;40℃温水浴快速解冻为最佳解冻方法;超低温保存前后的植株株高、根长等田间生长指标无明显区别;SSR分子标记未发现差异条带。[结论]含水量是影响超低温保存效果的重要因素;建立起一套安全可靠的人参裂口种子超低温保存技术;超低温保存后的材料表现型及基因型均未发生改变,遗传稳定性好。     

植物花粉影响因素和保存方法研究进展

花粉是植物种质的主要形式之一，包含该物种的所有基因类型。植物花粉的保存研究对完善种质资源保存方法及加速育种进程具有重要意义。为了满足种质资源保存以及杂交育种工作的需求，笔者阐述了花粉类型、基因型及化学成分、环境因素等对植物花粉生活力的影响；总结了植物花粉的收集和花粉生活力的主要测定方法以及有机溶剂保存、低压保存、低温保存、超低温保存等植物花粉的主要保存方法；提出超低温保存技术将成为花粉保存和研究的重要方向，仍需进一步深入研究植物花粉不同保存方法的保存机理。以期为研究不同植物花粉的长期高效保存方法提供参考。     

超低温(-196℃)保存杂交水稻恢复系花粉的研究

试验研究了杂交水稻恢复系芬粉液氮超低温（－１９６℃）保存的技术。结果表明,含水量在５．８０％至２９．６０％范围内的花粉,超低温保存后,超低温保存后,田间授粉均能桔实,含水量１３．２４％的花粉结实率最高,达６５．０％。经统计分析,含水量１３．２４％和９．１１％的花粉,其结实率与对照新鲜花粉无显著差异。试验表明,花粉干燥的适宜温度为１０℃,此温度下干燥,对花粉生活力影响较小。花粉的生活力染色测定以联苯     

合欢和青杄种子超低温保存研究

为了探讨超低温保存技术应用于园林树木种子的适应性,研究了合欢和青杄种子超低温保存.结果表明:(1)采用直接投入法,除了合欢部分种子进入液氮后炸裂外,2种种子液氮保存后都有萌发能力,但其发芽率、发芽势变化不同.在自然含水量下,液氮保存后合欢种子发芽率和发芽势较对照都显著提高;青杄种子发芽率明显降低,而发芽势则与对照没有显著差异.(2)不同树种用于液氮保存的适宜种子含水量不同.合欢种子在10％的自然含水量下保存于液氮中发芽率、发芽势和发芽指数最高;而青杄种子需经过干燥脱水,含水量在4％时,保存后种子萌发力较好.结果显示,常温保存下种子寿命有较大差异的园林树种都实现了超低温保存.因此,该技术在园林树木种子长期保存中有应用潜力.     

杏种子与种胚的超低温保存研究

含水量为６．９％带有内果皮的种子，以－５Ｃｍｉｎ＾－１速率降至－８０℃，放入ＬＮ２，在室温缓慢解冻，成活率可达９１．５％。去掉内果皮含水量为７．１％的种仁，以上述方式保存，成活率也可达到８８．２％。含水量是超低温保存杏种子最重要的因素。研究表明：冰冻保护剂ＤＮＳＯ对杏种子的超低温保存影响不大。含水量为４．８％￣８．１％去掉子叶的种胚超低温保存后ＴＴＣ染色成活率为８２．８％，并能在ＭＳ培养基上发育为     

白掌花粉活力检测及其超低温保存研究

对引种的20种白掌鲜花粉的活力、含水量及室温下寿命进行测定,并研究20种白掌花粉活力超低温保存2年内的变化。结果表明：所试验的白掌鲜花粉萌发率约为28%~59%,品种间鲜花粉的活力差异较大;测试的各个白掌品种鲜花粉的含水量约为10%~13%;所试验的白掌品种鲜花粉的寿命均不超过15天;同一白掌品种间,超低温保存时间的长短会使白掌品种花粉活力产生变动;超低温保存2年,所有测试白掌品种的花粉活力均没有损失,部分品种花粉活力还有明显提升,说明超低温保存为白掌花粉种质资源长期保存的一种理想方法。     

苹果休眠茎尖的超低温保存研究

苹果金冠品种的休眠芭尖经３种不同方法超低温保存后,均获得成功,存活率达到８３％。休眠茎尖经受了冬季的深冷驯化和具有较低的含水量,因而成为超低温保存的良好试材。经过玻璃化液（ＶＳ３：５０％甘油＋５０％蔗糖）预处理８０ｍｉｎ后或经蔗糖溶液预培养产于无菌空气中干燥脱水至含水量３０％左右后,休眠茎尖可直接投入液氮进行超低温保存。保存一的休眠茎尖经离体２后可直接再生植株。试验进一步验证了试材生理状态的选择是     

超低含水量的花生种子贮藏研究

试验以花生种子为材料,硅胶作干燥剂,超干后的花生种子含水量为3％,2％,1％,分别密封贮于O℃,室温,45℃。结果表明:超干后立即发芽,各级超低含水量种子生活力与原始含水量的生活力没有明显差异,种子在室内回湿后发芽,各级超低含水量种子生活力与原始的亦无明显差异,超干燥至1％水分,花生种子无干燥损伤。回湿后的活力指数比不回湿的高,回湿可以提高超低含水量的种子活力。贮存10,20,30个月后测定生活力表明:最耐贮存寿命最长的是2％含水量的种子,耐贮程度排列次序是2％>3％>1％>4.4％。花生种子超低含水量的临界水分是2％,室温贮存的种子最佳含水量3％～2％,0℃贮存的种子最佳含水量4.4％～3％。     

糯小麦种子超低温保存适宜含水量的研究

以5种不同含水量的糯小麦W1032种子为试验材料,进行液氮超低温保存试验,测定种子的活力指标及有关酶的活性.结果表明:种子含水量为11.88％的处理,其幼苗生长测定、冷浸试验、加速老化试验、电导率测定、模拟田间出苗率测定的主要活力指标以及ADH、POD、CAT、SOD、LOX的活性,与对照相比差异均不显著.说明糯小麦种质资源可以进行液氮超低温保存,其适宜含水量为12％.     

Storage of maize (Zea mays L.) pollen at −196°C in liquid nitrogen

Summary The water content of pollen has a decisive influence on its storability in liquid nitrogen. Pollen with an initial high water content cannot be stored successfully at extremely low temperatures, so a certain degree of drying must be carried out before storage. Provided the viability of the pollen is not significantly reduced during drying, the pollen remains viable and fertile when kept at –196°C.     

Effect of Boron on Seed Yield in Lucerne (Medicago sativa L.)

The present study aimed at studying the effect of boron on pollen characteristics, translocation of water soluble sugars and its importance as a specific nutrient for seed production in lucerne. Aquous solutions of borax (0, 2500, 5000, 7500, 10 000 and 20 000 ppm) were sprayed at flowering stage. After 20 days, the fresh flowers were collected from the plants of all the treatments separately. The pollen was dusted on glass slides containing Muntzing's mixture for staining. After 6 hours, the data on pollen size, stainability and germination were recorded in 10 randomly selected microscopic fields. The estimation of water soluble sugars and boron content in flowers was done by standard methods. Data on grains per pod, grains per inflorescence and 1000 seed weight were recorded at seed maturity. With increasing rates of applied B, pollen germination, water soluble sugars, boron content and number of seeds per pod and per inflorescence increased but pollen fertility decreased. The pollen size and 1000 seed weight was not affected by boron concentrations. The results indicate that boron plays a definite role in increasing the seed yields through stimulating the physiological processes during reproductive phase.     

Pollen-handling protocol and hydration/dehydration characteristics of pollen for application to long-term storage

Summary The National Seed Storage Laboratory in Fort Collins, Colorado, is investigating pollen storage as a practical means for storing germplasm of clonally-held species. Careful regulation of pollen moisture content is necessary to safely store pollens and perform accurate in vitro germination tests. A series of dehydration and hydration curves were generated for Pinus ponderosa Dough. ex P. Laws., Picea pungens Engelm., and Carya illinoensis (Wangenh.) K. Koch pollens using five saturated salt solutions and water. Equilibrium moisture contents (EMCs) were also determined for Typha latifolia L., Phoenix dactylifera L., Corylus avellana L., and Zea mays L. Although rates of dehydration and hydration, and EMC varied with salt, pollen, and temperature, the pollens tested did survive the drying procedures and could successfully be stored in liquid nitrogen.Abbreviations NSSL - National Seed Storage Laboratory - EMC - Equilibrium Moisture Content - LN - Liquid Nitrogen     

枇杷种子脱水敏感性的初步研究

枇杷（EriobotryajaponicaL.）种子成熟采收时含水量高达58.7％，其中子叶含水量为55.3％，胚轴的含水量为73.2％。新鲜种子的发芽率和活力指数分别为90％和0.81。轻度脱水能较大幅度地提高发芽率和活力指数。但随着脱水程度的不断加深，子叶和胚轴的超氧物歧化酶（SOD）活性下降，丙二醛（MDA）含量和种子浸泡液的电导率增加，种子活力迅速降低。当子叶和胚轴的含水量分别降至35.5％和28.0％时，种子发芽力完全丧失。枇杷种子脱水敏感的一个重要原因就是在脱水劣变过程中，发生了膜脂过氧化作用，从而使膜脂含量下降，膜结构和功能受损，最终导至种子活力丧失。     

Production of polyhaploids of hexaploid wheat using stored pearl millet pollen

The effects of drying and freezing on viability of pearl millet pollen were examined with the aim of using stored pollen in polyhaploid production of hexaploid wheat. Freshly collected pollen of pearl millet line NEC 7006 with 55% water content, germinated at a frequency of 80%. Pollen that was dried for two hours to 6% water content showed 50% germination frequency and maintained similar frequencies after the freezing process. In crosses of hexaploid wheat variety Norin 61 with fresh pearl millet pollen, embryos were obtained at a frequency of 27.6%. In crosses with pollen stored at -196 °C, -80 °C and -20 °C for one month, embryo formation frequencies ranged from 27.5 to 17.4%. After five and twelve months of storage, the frequencies ranged from 29.7 to 14.6% at storage temperatures of -196 °C and -80 °C, and from 8.0 to 3.2% at -20 °C, indicating significant differences among storage temperatures. However, no significant frequency difference was found among pollen water contents at the time of collection. All plants regenerated from crosses with pearl millet pollen stored for five months were wheat polyhaploids. These results suggest that stored pearl millet pollen is an efficient medium for producing polyhaploids in hexaploid wheat. This revised version was published online in August 2006 with corrections to the Cover Date.     

纯果肉型枇杷饮料的研制

以新鲜枇杷为原料,经二次超高压处理,不添加任何食品乳化稳定剂,依靠高压处理后形成的稳定体系,研制出具有营养、健康、保健作用的纯天然果肉混合型枇杷饮料。以感官评价为指标,采用L9(34)正交试验,得出最优工艺条件为:果肉与水的质量比为1∶1,糖酸比为100,固形物含量为10%~11%,制得的产品酸甜适合,色泽鲜亮,口感爽滑。     

不同贮藏温度条件下3个烟草品种花粉活力、形态及生理指标变化

以烟草品种N. rustica、Maryland 609和云烟85花粉为试验材料,研究不同贮藏温度条件下参试烟草品种花粉的活力、形态及相关生理指标的变化。以烟草品种N. rustica冻存花粉活力检测结果为例,在-196℃和-80℃保存条件下,花粉贮藏16个月后活力分别为0.64±0.06和0.65±0.09,与贮藏前0.66±0.04相比,未出现显著下降,而4℃贮藏的花粉在保存5个月后即丧失活力。花粉电镜图片显示,在-196℃和-80℃贮藏条件下,花粉形态仍然规则饱满,而4℃条件下贮藏16个月的花粉则发生皱缩、畸形,萌发沟扭曲。-196℃贮藏条件下N. rustica的花粉可溶性糖含量（309.276mg/g）、可溶性蛋白含量（55.216mg/g）、游离氨基酸总量（15.817μmol/mg）、脯氨酸含量（1.596mg/g）、超氧化物歧化酶（SOD）活性（4.284U/g）均显著高于4℃贮藏条件下的花粉;-80℃贮藏条件下花粉脯氨酸含量（1.626mg/g）和SOD活性（5.546U/g）高于-196℃（液氮）条件下贮藏的花粉,可能与不同温度下花粉冻结速度有关。结果表明,-196℃和-80℃条件下保存对烟草花粉的活力保持更有利。     

乙烯与水稻细胞质雄性不育的关系

从幼穗发育的IV到VII期,水稻细胞质雄性不育系(珍汕97A)幼穗和叶片的ACC含量和乙烯释放速率均高于其保持系(珍汕97B)。外施乙烯释放剂乙烯利使保持系花粉可育度明显下降;外施ACC合成酶抑制剂AVG引起两系幼穗ACC含量和乙烯释放速率下降,并使不育系花粉育性得以部分恢复,而在外施AVG的同时再施以乙烯利则AVG的恢复作用消失。     

Selection on pollen for linolenic acid content in rapeseed, Brassica napus L.

In order to enhance the economic value of edible rapeseed oil, an improvement of quality is necessary. Mutagenesis of rapeseed resulted in a low linolenic acid content and a low ‘linolenic acid (CIS: 3) level to linoleic acid (CIS: 2) level’ ratio, that is, the linoleic desaturation ratio (LDR), in the seeds of the Canadian variety ‘Stellar’. As an early breeding marker for low linolenic acid content, the pollen fatty acid composition was determined on 80 doubled haploid plants derived from a single F₁ hybrid obtained from a cross between ‘Stellar’ and a high CIS: 3 variety ‘Drakkar’. Fatty acid analysis on seed and pollen showed that the low CIS: 3 and the low LDR traits from the ‘Stellar’ variety were expressed in pollen and in seeds, and that a very close correlation (r = 0.88) existed between seed and pollen for these two traits. The inheritance of these traits is controlled by two major genes with additive effects, both in seed and pollen. However, minor genes also appeared to be expressed in pollen and seed. These genes may allow the production of plants with lower CIS: 3 levels than that of the low linolenic acid content parent. The efficiency of this new tool for early screening in breeding programmes is discussed.