积雪处理和室内干燥贮藏对6种荒漠植物种子活力的影响

以古尔班通古沙漠6种荒漠植物种子为材料,以同期收获室内干藏种子为对照,研究了3种积雪处理对其种子活力的影响.结果表明,积雪处理造成灰绿藜和驼绒藜种子萌发率显著下降,且导致积雪处理后灰绿藜未萌发种子丧失活力而死亡,诱导驼绒藜未萌发种子部分进入休眠并造成一定数量种子丧失活力;对雾冰藜和驼绒藜种子萌发率影响不显著,未诱导2种植物未萌发种子进入休眠或造成种子死亡;未能解除小车前和亚麻芥种子休眠,但能使大多数未萌发种子保持活力.     

华北驼绒藜种子发育过程中内源激素变化动态的研究

以3种结实类型华北驼绒藜的种子(正常发育型,轻度败育型,高度败育型)为材料,对种子发育过程中内源激素含量动态进行了观察测定.结果表明:正常发育型华北驼绒藜种子IAA和GA,含量随着种子的发育呈持续上升趋势,轻度败育型和高度败育型种子IAA和GA3含量在种子发育初期(花后10 d)同时出现明显下降,随后开始上升;ZR含量在种子发育过程中呈单峰曲线,败育型种子的ZR含量要显著低于正常发育型;ABA含量在种子发育前期较低,随着种子的发育呈上升趋势,但3种结实类型种子间的差异并不是很大;在种子发育初期(花后10 d),正常发育型与两种败育类型种子(IAA GA3 ZR)/ABA的比值差异达到最大,说明内源激素动态变化及它们之间的比例平衡关系与华北驼绒藜胚胎败育有着密切联系.     

施肥对华北驼绒藜种子耐贮性的影响

为探索施肥对华北驼绒藜种子耐贮性的影响,对华北驼绒藜追施氮肥、钾肥和喷施微量元素,在种子收获当年秋季和收获后6个月、10个月、14个月进行萌发特性的测定。结果表明:在华北地区,对3~6年生华北驼绒藜单施氮肥80 g/株可显著提高种子活力指数;单独使用4种微肥均能使种子的发芽率、发芽势、发芽指数及活力指数显著高于对照,但影响程度略有不同,B最高,Mn次之,Zn最低,4种肥料混合使用活力指数显著低于对照。氮肥的使用利于华北驼绒藜种子的贮藏,但要注意施用量和施用方式;微量元素的使用使贮藏种子活力指数显著低于对照,不利于华北驼绒藜种子的贮藏。进行种子生产时,一定要慎重使用微量元素。     

华北驼绒藜种子发育生理与形态特征比较研究

测定华北驼绒藜不同发育程度种子含水量、千粒重、萌发特性,观测种子发育过程中形态特征,以了解华北驼绒藜种子成熟度、形态特征和种子活力的关系,为生产中确定适宜收获时期提供依据.结果表明:花后40 d时种子含水量为39.89％,趋于稳定;干物质积累在花后36 d增长趋于平稳,40 d积累停止,此时种子千粒重为1.69g,发芽率达到峰值,为98.7％.在授粉后10～12 d发育成16细胞原胚,14 d发育成球形原胚,15～17 d发育成心形胚,授粉后25 d胚体发育为成熟胚.以上试验结果表明,华北驼绒藜种子适宜的收获时间为花后36 d.     

不同贮藏条件对驼绒藜种子寿命的影响

不同含水量驼绒藜种子在室温、4~5℃和-18℃条件下贮藏4年,适度超干处理能延长种子的贮藏寿命。室温和低温下贮藏11个月后,超干燥(MC 5.28%~3.89%)和低温种子的丙二醛(MDA)含量明显地低于未超干燥种子(MC7.47%);而种子活力、脱氢酶活性和抗氧化酶POD和CAT的活性均显著地高于未超干燥种子。室温下贮藏48个月后,超干种子(MC 4.84%~3.41%)的活力与低温贮藏种子同等水平。超干燥贮藏下,在一定时期内驼绒藜种子活力保持较高水平;对脂质过氧化的抑制作用是提高超干燥种子耐贮藏性的生理原因之一。     

华北驼绒藜花粉萌发特性及不同授粉方式对其结实率的影响

为寻找华北驼绒藜结实率低、群落退化的原因,在栽培条件下对其花粉生活力、寿命、柱头萌发率与结实率的关系进行了相关性研究。采用同株、异株、自然授粉处理华北驼绒藜,同株授粉结实率(81.53%)显著低于异株授粉(88.6%)和自然授粉(92.6%)的结实率;采用TTC法对华北驼绒藜花粉寿命和生活力的研究结果表明,其平均寿命为6d,最佳授粉时间为1~3d,生活力达95%左右,不存在花粉败育和短命的问题,即不存在小孢子发育障碍。3种授粉方式处理后,采用荧光显微镜观察华北驼绒藜花粉在柱头上的萌发率,萌发高峰集中在授粉后3~4h,萌发率达90%以上,三者不存在显著差异,即华北驼绒藜不存在花粉与柱头的识别障碍。结实率与花粉在柱头萌发率的相关分析结果表明,二者不存在相关性。研究初步认为,同株授粉产生结实率低的原因可能发生在授精或胚胎发育过程,有待进一步研究。目前,华北驼绒藜野生群落严重退化,植被密度减少,可能存在大量自株授粉是造成群落退化的原因之一。     

辣椒果实成熟度、种子质量及种子主要营养成分间的相关性

植物果实(或种子)的成熟度是影响植物种子质量的重要因素。本文旨在通过对辣椒果实成熟度、种子质量和种子主要营养成分,以及种子主要营养成分与种子活力的相关性方面进行研究,为提高辣椒种子质量,改进种子检验、种子活力测定手段提供参考。材料和方法本试验于1989年2～10月在西北农业大学进行。供试材料为21号牛角椒。试验分田间和室内两部分。     

不同小麦品种(系)的存放种子活力比较研究

为发掘利用高活力小麦种质材料,揭示不同小麦品种间(系)的种子活力差异及其内在生理原因,本研究以置于常温种子库老化6年的180个小麦品种(系)的种子为材料进行了种子活力比较研究。结果表明:不同小麦品种(系)间发芽率存在显著差异,其中35个小麦品种(系)的种子完全失活、不能发芽,种子活力最高的3个品种分别为豫麦18(92%),西农3517(76%)和浏虎98(72%);测定了种子浸出液电导率、种子含水量和籽粒品质性状并与发芽率进行了相关分析,发现发芽率与电导率和籽粒淀粉含量呈极显著负相关,与含水量呈显著负相关,但与籽粒总蛋白质含量相关不显著;进一步对种子活力高低差异显著的6个品种(系)进行了种子萌发关键激素赤霉素(GA3)和脱落酸(ABA)的测定,发现3个高活力小麦品种(系)(豫麦18、西农3517、浏虎98)种子中GA3/ABA的比值均显著高于3个低活力品种(系)(西农2003、洛麦21和陕麦107)。本研究表明,种子活力性状在小麦种质资源中存在广泛变异,植物内源激素GA3和ABA的相对含量是影响种子活力高低的关键因素。     

北美驼绒藜不同世代间核型变异分析

采用常规压片法对北美驼绒藜的4个世代进行了核型变异分析,结果表明:北美驼绒藜各世代体细胞染色体数目为2n=18,均为二倍体,核型公式均为2n=2x=18=18m,其核型均属1A型.北美驼绒藜的4个世代间无染色体数量变异,但存在结构变异,主要表现在染色体绝对长度、染色体长度组成、染色体长度比、平均臂比等方面,其中,染色体绝对长度变异系数较大.     

不同棉花品种种子活力对低温和人工老化胁迫的反应差异

为探讨棉花种子活力的品种差异及不同种子活力测定方法对棉子活力结果的影响,以17个棉花主栽品种(系)为材料,用简化的标准发芽、低温发芽和人工老化发芽3种方法测定棉花种子活力,并分析种子物理性状与种子活力的相关性。结果表明:3种活力测定方法下不同品种间种子活力均存在较大差异,各活力指标表现趋势也不一致,低温条件主要抑制种子幼苗的生长势,老化条件则主要抑制种子的发芽率。简化的标准发芽的活力指数与2种逆境发芽下的活力指数间的相关性较低。对3种测定方法的种子活力指标进行聚类分析,筛选出中棉所102、新陆中42、湘杂7号、XG39K5、屯杂6号及皖杂9号等高活力品种。低温和人工老化发芽条件显著降低了种子活力与种子各物理性状间的相关性。种子密度和健子率在不同发芽条件下均与种子活力关系最密切,可作为判断棉花种子活力大小的物理指标。     

Oxidative damage in forage rape (Brassica napus L.) seeds following heat stress during seed development

A short period (240°C hr; Tb = 25°C) of heat stress (30°C day/25°C night) during forage rape (Brassica napus L.) seed development or at seed physiological maturity can reduce seed vigour, but the extent of oxidative damage associated with this short heat stress was not known. Heat-stressed seeds were assessed for malondialdehyde (MDA) content, hydrogen peroxide (H₂O₂) accumulation, antioxidant enzyme activity, adenylate energy charge and seed ultrastructural integrity, and compared with that of non-heat-stressed seeds. Heat stress increased both MDA content and H₂O₂ accumulation by 35%–50%, reduced antioxidant enzyme activity by between 12% and 67%, and significantly reduced adenosine energy charge. Transmission electron microscope images showed clear evidence of seed deterioration in heat-stressed seeds, including ruptures in cell wall and plasma membranes, fused lipid bodies and damaged mitochondria. Heat stress at physiological maturity caused more oxidative damage than the same heat stress during seed development. Seed vigour decreased as H₂O₂ accumulation increased and antioxidant enzyme activity decreased, but no direct relationship between lipid peroxidation and seed vigour was established. The extent of damage resulting from even shorter periods of heat stress (<240°C hr) before or at seed physiological maturity requires investigation.     

Wide genetic variation in phenolic compound content of seed coats among black soybean cultivars

Black soybeans have been used as a food source and also in traditional medicine because their seed coats contain natural phenolic compounds such as proanthocyanidin and anthocyanin. The objective of this research is to reveal the genetic variation in the phenolic compound contents (PCCs) of seed coats in 227 black soybean cultivars, most of which were Japanese landraces and cultivars. Total phenolics were extracted from seed coats using an acidic acetone reagent and the proanthocyanidin content, monomeric anthocyanin content, total flavonoids content, total phenolics content, and radical scavenging activity were measured. The cultivars showed wide genetic variation in PCCs. Each of the contents was highly correlated with one another, and was closely associated with radical scavenging activity. PCCs were also moderately associated by flowering date but not associated by seed weight. Cultivars with purple flowers had a tendency to produce higher PCCs compared with cultivars with white flowers, suggesting that the W1 locus for flower color can affect phenolic compound composition and content. Our results suggest that developing black soybean cultivars with high functional phenolic compounds activity is feasible.     

化控种衣剂对大豆籽粒灌浆过程及产量形成的影响

以垦农4号为材料,研究了化控种衣剂和常规种衣剂对大豆籽粒灌浆过程和产量形成的调控,探讨了内源激素作用的生理机制。结果表明,大豆应用化控种衣剂可以提高生育后期叶源和根源的生理活性;内源激素含量的变化利于籽粒内容物的充实和产量的形成;应用化控种衣剂平均比常规种衣剂增产13.9%。     

油菜(B.napus L.)硼素营养与结实性的研究

硼营养不足,油菜植株各器官含硼量均下降,下降幅度因器官而异,而以花器官下降幅度最大。缺硼时,花器发育异常,雄蕊在解剖生理上的异常现象尤为突出,严重时花粉败育,花蕾脱落,甚至出现颗粒无收的现象。花粉败育表现为花粉囊空瘪,核质解体,无孢原组织分化,绒毡层发育异常,小孢子原生质团溢出药壁外等现象。硼营养不足降低了花药     

Seed proteins of the wild and the cultivated Amaranthus species

The 13–21% variation in seed protein content was observed in wild and cultivated forms of amaranth. Seed proteins of amaranth are highly nutritive and composed presumably of easily digestable albumins and globulins (over 50% of total protein); of 20.8% alkali-soluble proteins-glutelins with similar nutritive value and only of 12% alcohol-soluble proteins-prolamins which are lacking in essential amino acids. The results of polyacrylamide gel electrophoresis (buffer pH being 3.2) indicate that seed proteins of amaranth are heterogeneous and compose of 38 bands which, by their electrophoretic mobility, can be tentatively assigned to four zones: A, B, C and D. By their protein patterns all Amaranthus species were assigned to 7 biotypes. The cytogenetic and electrophoretic comparison enabled us to determine the degree of diversity among amaranth forms studied. The phylogenetic relationship between A. paniculatus L. and A. hybridus L. was confirmed. A relationship was also supposed between these two species and A. lividus L. and between A. powellis L. and A. deflexus L. which by their electrophoretic patterns belong to the same biotype. A taxonomic classification of 5 samples whose classification has not been done yet was performed, as well as of cultivars Elbrus and Progress which were assigned to specious A. edulis L. It was confirmed that the method of electrophoretic analysis of seed storage proteins is very promising for detecting the phylogenetic relationship between Amaranthus species. This revised version was published online in July 2006 with corrections to the Cover Date.     

不同类型华北驼绒藜生殖特性及种子生产性能评价

华北驼绒藜野生群落中存在明显的种内生殖差异,对4种类型华北驼绒藜的生殖生物学和生产性能的研究结果表明,高产、早熟类型华北驼绒藜(T-1-A)种子产量高(69.0g/株),株型紧凑,生育期短(151d),千粒重(2.64 g),结实率(79.7%),饲草产量(140g/株),种子成熟度(83%)明显高于晚熟类型,具有较高的生产性能和育种前景.     

Genotypic lipoxygenase variation in soybean seeds and response to nitrogen nutrition

Decreasing the lipoxygenase content of soybean (Glycine max (L.) Merr.) seed is a prerequisite for its increased use in human foods. These investigations aim to analyse the variation of lipoxygenase contents in relation to the genotype or the nitrogen nutrition of the plant. Four genotypes from a divergent selection for N₂ fixation and the recurrent parent, Weber, were grown in pots, and two Bradyrhizobium japonicum strains (G.49 and SMGS1) were used. Dinitrogen fixation was estimated in situ using the acetylene–reduction assay. The lipoxygenase activity was determined polarographically on seeds taken from plants grown under controlled conditions in the presence or absence of symbiotic N₂ fixation. The large genotypic variation observed for the lipoxygenase contents was enhanced by high N₂ fixation. The variation range of lipoxygenase contents, which was obtained through the combination of the genotypic variation and the N₂ fixation activity, was relatively large with a ratio of 2 on a seed dry–weight basis and a ratio of 2.6 when the total proteins were considered. Decreased lipoxygenase content and increased total protein content can thus be considered in parallel in a genetic context, together with more efficient N₂ fixation.     

不同层积条件下滇重楼种子的生理变化

为揭示滇重楼种子休眠的生理生化变化规律,为滇重楼的栽培提供科学依据。对两种条件下层积160天内种子的胚率变化、贮藏物质的变化、POD与SOD活性进行了测定。结果表明: 整个层积过程中,滇重楼种子胚率显著增加,可溶性糖、可溶性蛋白、淀粉含量显著降低,POD活性显著升高;在云南西双版纳自然大田条件下种子,胚率高达11.59;可溶性糖、可溶性蛋白、淀粉含量分别降低到3.14mg/g、 2.72mg/g、 24.56mg/g, POD活性增高到10.35 U/(g*min)。与恒温层积相比,大田条件下种子各生理指标变化规律较好,更有利于其种子萌发。     

硝基苯胁迫对水稻种子萌发和幼苗生理特性的影响

在试验水培条件下,研究不同浓度硝基苯对水稻种子萌发和幼苗生长的影响.结果表明：硝基苯明显抑制水稻萌发过程中的根伸长生长,发芽率变化不明显;受硝基苯胁迫,水稻幼苗叶片叶绿素含量随硝基苯浓度增加而降低,过氧化物酶活性和丙二醛含量均随浓度的增加呈先增加后下降的趋势,25 mg/L硝基苯处理时过氧化物酶活性及丙二醛含量为最大值.