不同活力花生种子子叶内肽酶活性及花生球蛋白的降解

花生种子人工劣变后活力下降,子叶内肽酶活性降低,花生球蛋白降解速率减慢。内肽酶同工酶也发生变化,种子在劣变过程中可能诱导新内肽酶产生。     

花生根瘤菌剂的贮存试验初报

花生根瘤菌剂的贮存试验初报宋玉清（辽宁省农科院土肥所微生物室,沈阳,１１０１６１）花生根瘤菌剂用于花生种子拌种,我省花生播种一般在每年的４月底５月初,而工厂生产就卜般从１１月开始生产,到第二年的３月结束。也就是说工厂干１１月份就有可能出产品,这些产,...     

酶水解制备花生粕多肽工艺的优化

目的：优化研究花生粕制备多肽的工艺。方法：采用酶法水解提取多肽、用总蛋白试剂盒（TP）双缩脲比色法在540nm处测定其含量。结果：用木瓜蛋白酶水解花生粕蛋白得到多肽的最佳工艺条件为：加酶量6 300u/g原料、温度45℃、底物浓度10%、酶水解时间5h。     

不同品种花生种子蛋白质的电泳分析

对中国花生（ＡｒａｃｈｉｓｈｙｐｏｇａｅａＬ．）５种不同类型的４６个栽培品种的种子蛋白质进行电泳分析。ＳＤＳＰＡＧＥ和ＩＥＦＳＤＳＰＡＧＥ（双向电泳）的结果显示,不同品种的花生种子蛋白多肽组成存在４种类型。与初步纯化的花生球蛋白及伴花生球蛋白的ＳＤＳＰＡＧＥ结果比较,花生种子蛋白组成的主要差异在于花生球蛋白亚基组成的不同,其中类型Ⅰ花生球蛋白主要含有４１ｋＤ、３８５ｋＤ和２个１８ｋＤ亚基,类型Ⅱ主要含４１ｋＤ、３８５ｋＤ、３７５ｋＤ和３个１８ｋＤ亚基,类型Ⅲ主要含４１ｋＤ、３８．５ｋＤ、３６．５ｋＤ和３个１８ｋＤ亚基,类型Ⅳ主要含４１ｋＤ、３８．５ｋＤ、３７５ｋＤ、３６．５ｋＤ和３个１８ｋＤ亚基。不同品种的伴花生球蛋白多肽组成基本一致。对不同类型８个品种种子蛋白的氨基酸组成进行测定,发现类型Ⅰ的含硫氨基酸含量较高。     

广东花生主要品种对黑腐病菌的抗性水平鉴定

【背景】寄生帚梗柱孢霉是花生黑腐病的病原菌,被我国列为重要的进境植物检疫性有害生物。该病菌2009年已入侵我国广东,造成花生植株基部腐烂而死亡,严重威胁花生生产安全。筛选与种植抗病品种是防控该病害的重要措施。【方法】收集广东推广种植的15个主要花生品种,通过人工接种方法,鉴定这些品种对花生黑腐病菌的抗性水平。【结果】15个供试花生品种中,湛红2号、湛油62等2个品种表现为抗病;湛油75、湛油82、粤油390、粤油410、仲恺花44、仲恺花99、汕油诱1号等7个品种表现为中抗;花育33号、汕油523、汕油辐1号、粤油18、湛油53等5个品种表现为感病;仲恺花332表现为高感。【结论与意义】目前广东生产上推广种植的花生品种多数对黑腐病菌表现为抗病或中抗水平,部分品种表现为感病或高感。该结果可为我省花生品种的推广与布局提供依据。     

花生种子的磁处理对其萌发及幼苗生长的影响

本试验着重研究了用交、直流磁场对花生种子进行处理后,在种子萌发及幼苗生长过程中产生的影响。结果表明,一定强度的交流或直流磁场对种子的萌发及幼苗生长有一定的促进作用。处理过的种子存放一年后,磁场对种子萌发的作用依然存在。     

活性氧对花生叶片大分子量DNA的损伤

花生幼苗叶片DNA分子量略大于23.1kb,甲基紫精或黄嘌吟-黄嘌吟氧化酶所产生的O_2~-对其结构有剪切或降解作用。活性氧清除剂SOD、甘露醇和硫脲在一定程度上抑制活性氧对DNA结构的损伤。     

伴花生球蛋白cDNA克隆及其在花生发育种子中的表达

利用伴花生球蛋白多克隆抗体,免疫筛选花生品种汕油523成熟子叶中期cDNA文库得到6个阳性克隆.经过DNA序列测定和同源性分析确定为2组(Ahyα和Ahyβ) ,2组序列之间的同源性为97%.Ahyβ与花生过敏原Ara h1 p17以及Ahyα与花生过敏原Ara h1p41b的核苷酸相同性达到99%以上.以Ahy-βcDNA为探针的Northern blot分析结果表明,伴花生球蛋白基因在发育的花生种子中大量表达,而在幼苗的叶片中不表达.对成熟中期花生子叶表达序列标签(EST)分析,获得了包括5种花生球蛋白、2种伴花生球蛋白、6种conglutin蛋白的EST共70条,占总转录本的17%.     

春秋花生种子细胞化学的比较研究

采用泉花10号,汕油71的春秋花生种子为材料,利用细胞化学方法,在环氧树脂厚切片中分别显示出下胚轴和子叶中的多糖、蛋白质和脂类,并对其数量、形态及分布进行比较.结果表明,春花生种子下胚轴细胞较大,且内部结构清晰,排列规则,发育充分,而秋花生种子成熟度较低.对于子叶细胞,在春花生中,其贮藏物质丰富含大量的脂体、蛋白体,排列紧密;而秋花生细胞内部结构疏松,液泡中尚未充满蛋白质,但淀粉粒似较多.这就从细胞学的角度解释了生产上采用春花生种子的优越性..另外,在方法上对环氧树脂厚切片中多糖、蛋白质、脂类的细胞化学染色方法和染色保存进行了讨论.     

Grassland composition affects season shifts in seed preference by Pogonomyrmex barbatus (Hymenoptera: Myrmicinae) in the Edwards Plateau, Texas

The effects of season and community composition as generated by livestock herbivory of differing intensity on seed species preference by Pogonomyrmex barbatus (F. Smith) were studied in a semiarid savanna on the Edward's Plateau, TX. Seasonal differences in nutrient requirements of the colony could lead to differential preferences for seeds harvested in spring and fall. Field cafeteria studies were conducted to test the hypothesis that late successional species, with their high nutrient content, would be chosen regardless of grazing intensity or season. Commercial seeds of known nutrient content were used to test the hypothesis that high protein levels would be chosen in spring and high carbohydrate levels in the fall. Naturally occurring seeds were differentially harvested and some were preferred regardless of relative availability. Total seed harvest in cafeteria experiments was higher in spring than in fall. Commercial seeds were harvested equally among treatments within a season; thus, nutrient selection was indistinguishable. Preference for native species was significantly different in both seasons but was influenced by a significant interaction with grazing treatments. Bouteloua curtipendula, a late successional mid-grass, was harvested significantly more in the spring than the fall and at higher rates in the heavily grazed treatment, rejecting the hypothesis that they would be chosen regardless of treatment or season. Seed preference for late successional grasses within heavily grazed communities may slow succession after grazing. During disturbance recovery, late successional species may be reduced by forager preference and rates of spring harvest.     

Studies on the Structure,Afterripening and Cytochemistry of Seeds in Eleutherococcus brachypus Harms

Seeds of Eleutherococcus brachypus Harms were flat-kidney-shaped and their seed coats were only composed of one layer of cells. Embryos with abundant protein in their cells were just at the heart-shaped stage and were capped by sacs formed from degenerating endosperm cells when seeds shed from their maternal plants. A large amount of stored protein grains and lipids existed in endosperm cells but no polysaccharide grains were present either in endosperm cells or in embryo cells. Viable seeds were only 9.27% of the total. The plump seeds germinated in the cultivated field after 18～19 months and their germinating rate was 1.67%. Besides, the content of protein decreased gradually and a few polysaccharide grains were stored in embryo cells during the process. The afterripening process of seeds stratified at different temperatures ended after 6 months and the cytochemistry features of the seeds were that the content of protein decreased gradually and numerous polysaccharide grains had been stored in embryo cells at the late heart-shaped embryo stage and retained till the mature embryo stage. The structure, afterripening and cytochemistry of seeds were compared between Eleutherococcus brachypus and Eleutherococcus senticosus. The poor quality of the seeds, longer time of afterripening in a natural state and much lower germination rate of E. brachypus are considered to be important reasons for the endangerment of this species. Somemeasures are suggested for its conservation based on the above facts.     

Seed Structure Characteristics to Form Ultrahigh Oil Content in Rapeseed

Background

Rapeseed (Brassica napus L.) is an important oil crop in the world, and increasing its oil content is a major breeding goal. The studies on seed structure and characteristics of different oil content rapeseed could help us to understand the biological mechanism of lipid accumulation, and be helpful for rapeseed breeding.

Methodology/Principal Findings

Here we report on the seed ultrastructure of an ultrahigh oil content rapeseed line YN171, whose oil content is 64.8%, and compared with other high and low oil content rapeseed lines. The results indicated that the cytoplasms of cotyledon, radicle, and aleuronic cells were completely filled with oil and protein bodies, and YN171 had a high oil body organelle to cell area ratio for all cell types. In the cotyledon cells, oil body organelles comprised 81% of the total cell area in YN171, but only 53 to 58% in three high oil content lines and 33 to 38% in three low oil content lines. The high oil body organelle to cotyledon cell area ratio and the cotyledon ratio in seed were the main reasons for the ultrahigh oil content of YN171. The correlation analysis indicated that oil content is significantly negatively correlated with protein content, but is not correlated with fatty acid composition.

Conclusions/Significance

Our results indicate that the oil content of YN171 could be enhanced by increasing the oil body organelle to cell ratio for some cell types. The oil body organelle to seed ratio significantly highly positively correlates with oil content, and could be used to predict seed oil content. Based on the structural analysis of different oil content rapeseed lines, we estimate the maximum of rapeseed oil content could reach 75%. Our results will help us to screen and identify high oil content lines in rapeseed breeding.     

Lipid peroxidation and peroxide-scavenging enzymes associated with accelerated aging and hydration of watermelon seeds differing in ploidy

Hydration offers an effective means for raising seed performance in many crop species. The objective of this study was to evaluate the effect of vermiculite hydration on germinability and several physiological activities related to vigor in artificially aged watermelon seeds differing in ploidy. Aging was achieved by incubating the seeds at 45°C and 79% relative humidity for 6 days, then the seeds were air-dried to their original moisture level (4.7%). Hydration was achieved by mixing the untreated and aged seeds with moist vermiculite No. 3 at 25°C for 24 h. The partially hydrated seeds were air-dried at 25°C for 36 h to 4.7% moisture level. Significant differences existed between unaged and aged seeds, with lower germination percentage and slower germination speed in the latter. Aging also increased lipid peroxidation and reduced the activity of peroxide-scavenging enzymes. The germinability of aged watermelon seed was restored partially by vermiculite hydration. The activities of protein synthesis and peroxide-scavenging enzymes in axis and cotyledon portions of the seeds were also increased by hydration treatment. The changes in germination and related physiological responses in relation to aging and hydration are similar in seeds differing in ploidy, despite differences in their germination performance, seed leakage, extent of lipid peroxidation and activities of peroxide-scavenging enzymes.     

Diplochory in western chokecherry: you can��t judge a fruit by its mesocarp

Western chokecherry (Prunus virginiana var. demissa, Rosaceae) is dispersed by frugivorous birds and carnivores, but it has large seeds that are potentially attractive to rodents that could act as seed predators and dispersers. Here, we quantify the benefits of primary dispersal by birds and secondary dispersal by scatter-hoarding rodents. In the fall, avian frugivores (mostly American robins, Turdus migratorius, and cedar waxwings, Bombycilla cedrorum) consumed 87% of the fruit crop and dispersed 67% of the fruit crop away from parent plants. Rodents removed 89% of seeds that simulated bird-dispersed seed rain from transects in riparian zones and 58% from transects in upland habitats. Rodents scatter-hoarded 91.6% of the seeds they removed, burying most in small caches (two to eight seeds) 8?C25?mm deep. About 39% of the seeds in spring caches produced seedlings. Inside rodent-proof exclosures, 52.1% of seeds buried to simulate rodent caches produced seedlings, 29.7% of which were still alive after 1?year. In contrast, only 3.8% of seeds placed on the soil surface, simulating dispersal by avian frugivores, produced seedlings. Seed dispersal by frugivorous birds likely contributes to colonization of unoccupied habitat through long-range dispersal and to escape from distance-dependent seed mortality near the parent plant. Despite seed losses, rodents offer short-range seed dispersal and bury seeds in more favorable sites for germination, improving seedling emergence and establishment. The combined mechanisms of seed dispersal significantly enhanced chokecherry seedling recruitment by providing more dispersal-related benefits than either frugivorous bird or scatter-hoarding rodents could provide alone.     

GEOGRAPHIC DIFFERENCES IN THE SEED GERMINATION OF PAPER BIRCH (BETULA PAPYRIFERA)

The effects of light and temperature on germination of paper birch (Betula papyrifera Marsh.) were examined in seeds from different geographic locations. Under continuous light at 14–18 C northern seed sources germinated more rapidly and achieved higher germination percentages than southern ones. Seed source influenced the range of temperatures over which germination occurred. Northern seeds had a wider temperature range than southern ones due to depression of the low temperature limit in northern seeds. At 15 C, seeds exhibited a photoperiodic-like response with progressive increases in germination as daily photoperiod was increased. This was not a true photoperiodic effect because seeds responded to the total amount of light rather than to the relative length of light and dark periods. It is suggested that at temperatures near 15 C, this response may be important in preventing fall germination. Prechilling at 3 C promoted subsequent dark germination in most seed sources tested, and northern seeds were much more sensitive to the treatments than southern seeds. In some seeds the prechilling stimulus was lost with protracted storage at 3 C; this was observed in both northern and southern seeds. Prechilling enhanced the seeds’ sensitivity to subsequent light. Although acquisition of the prechilling stimulus does not serve to measure the length of winter in these seeds, the high light sensitivity induced by prechilling probably accelerates spring germination. Northern seeds typically had thinner, more translucent pericarps than their southern counterparts.     

赤霉素和温水浸种对紫斑牡丹种子下胚轴萌发及其种胚解剖结构的影响

以紫斑牡丹种子为试验材料,采用不同浓度(0、100、300、500 mg/L)赤霉素(GA3)浸种和不同温度温水浸种(25、30、40和50℃)处理,考察各处理种子生根率的变化,并通过透射电镜观察不同生根发育时期种子种胚超微结构,探究赤霉素和温水浸种处理解除紫斑牡丹种子休眠进程中种胚超微结构变化以及这种变化与休眠解除的相关性。结果表明:(1)GA3和温水浸种均明显提前了紫斑牡丹种子生根时间,并以300 mg/L GA3和40℃温水处理的生根效果最好,分别较对照提前14.7 d和16.0 d,生根率分别达62.33%和67.00%。(2)光学显微镜观察发现,GA3、温水浸种处理较对照组紫斑牡丹种胚子叶的上、下表皮细胞形状及排列方式无明显影响,但其厚度均变薄,维管束结构明显,以300 mg/L GA3和40℃温水浸种处理生根效果最佳。(3)透射电镜观察发现,在各GA3浸种和温水浸种处理下,紫斑牡丹种子萌发前期,种胚子叶脂类物质出现降解现象,脂体呈大小不一的圆形或块状分布在细胞壁周边,数量明显减少,细胞核明显,核仁清晰,出现少量线粒体,细胞质内开始有蛋白质积累,在液泡的周围形成蛋白质沉积物;在种子萌发后期,种胚子叶细胞内物质稠密,脂体已降解融合成较大块状,细胞中储存的营养物质基本降解完全,内质网、高尔基体、线粒体等细胞器出现,结构更加完整,表明此时细胞内物质代谢活动加强,种子休眠解除,且300 mg/L GA3、40℃温水浸种处理种子种胚子叶结构变化最为明显。研究发现,300 mg/L GA3浸种和40℃温水浸种均可显著提高种子的萌发率,且40℃温水浸种的效果更好,在实际生产中建议使用温水浸种法。     

Seed storage protein variation in Arachis species.

Seventy-two accessions, representing 22 species from sections Arachis, Erectoides, Extranervosae, and Triseminalae of the genus Arachis, were screened for seed storage protein polymorphism. Variation was detected between sections, between genome types, between species, and in some cases between different accessions of the same species or different seeds of the same accession. Arachis duranensis and one accession of A. cardenasii were found to have identical protein patterns. The greatest dissimilarity was found between species of the section Extranervosae and species of the section Triseminalae. Those of section Erectoides showed much similarity with some species of section Arachis. Protein polymorphism was shown to distinguish the two subspecies of A. hypogaea (fastigiata and hypogaea) in 27 of 28 cases. The seed protein profile of A. monticola was a combination of seed protein profiles from the two A. hypogaea subspecies. The relatedness between the various species was calculated and those that had the greatest similarity with A. hypogaea were A. spegazzinii and A. batizocoi.