银杏花粉萌发生长与分枝式花粉管形成的观察

本研究采用半薄切片法和扫描电镜等技术对银杏（Ginkgo bilobaL.）花粉管的体内萌发与生长以及花粉的离体培养进行了观察,结果表明：（1）银杏花粉粒通过传粉滴收缩后到达胚珠珠孔处,并经珠孔道进入贮粉室内停留,约7 d后花粉粒开始萌发;（2）贮粉室内的花粉最初萌发出的花粉管与花粉粒的四细胞轴几乎垂直,表现出明显的侧向萌发特征。初始花粉管在贮粉室内的生长方向无规律,有的通过一定的贮粉室空间向较远的珠心组织细胞间隙生长,有的直接进到较近的珠心组织细胞间隙,花粉管的生长不损伤珠心组织细胞;（3）花粉离体培养过程中会迅速发生水合作用,花粉粒由船形变为圆球形。48 h后花粉外壁脱落,管细胞膨大,花粉管自管细胞膨大处萌发。随着花粉管的生长,管细胞核移动进入花粉管内,而生殖细胞仍留在花粉粒内。伸长的花粉管可分为淀粉粒区和透明区,花粉管末端易形成多种类型的分枝。花粉管内原生质呈喷泉状流动。     

大豆种子萌发过程中子叶细胞超微结构和ATP酶活性动态研究

采用磷酸铅沉淀的电镜细胞化学方法,研究大豆种子萌发过程中,子叶细胞超微结构变化与ATP酶活性的消长。子叶细胞的ATP酶活性主要定位在质膜。在种子萌发的0-3天,子叶细胞贮存蛋白质和油脂大量急剧降解,并快速转运到胚,质膜ATP酶活性较高。萌发的6-9天,子叶细胞内含物大部分消解,蛋白体膜相互融合形成大液泡,原质体开始有稀疏的片层结构,ATP酶活性渐弱至无。萌发第12天,原质体的片层堆叠成基粒,子叶细胞转为同化器官,制造养分,质膜再度呈现较强的ATP酶活性。子叶细胞质膜ATP酶活性反应子叶细胞生理代谢状态。     

5种农作物锈病孢子的扫描电镜观察

应用扫描电子显微镜观察小麦叶、蒜叶、蚕豆叶、玉米叶和葱叶上的锈病孢子形态特征,观察指标包括孢子的形状、孢子的表面特征以及孢壁纹饰等。结果表明孢子形状各异但以不规则椭圆状为多,孢子表面均具有刺和芽孔,孢壁呈光滑状、浅波状、皱波状和颗粒状纹饰。不同的孢子在形态上呈现一定的差异,通过形态的差异可以区分不同的孢子,为锈病病原体鉴别提供一定的依据。     

RCS1, a gene involved in controlling cell size in Saccharomyces cerevisiae

Cloning and sequencing of RCS1, Saccharomyces cerevisiae gene whose product seems to be involved in timing the budding event of the cell cycle, is described. A haploid strain in which the 3'-terminal region of the chromosomal copy of the gene has been disrupted produces cells that are, on average, twice the size of cells of the parental strain. The critical size for budding in the mutant is similarly increased, and the disruption mutation is dominant in a diploid heterozygous for the RCS1 gene. Spores from this diploid have a reduced ability to germinate, the effect being more pronounced in the spores carrying the disrupted copy of RCS1. However, disrupted cells recover from alpha-factor treatment equally as well as wild-type cells.     

DIMETHYL SULPHIDE FORMATION IN MALT—EFFECT OF MALTING CONDITIONS

The dimethyl sulphide (DMS) content of kilned malt, and, presumably, the level of precursor in green malt, is significantly affected by malting conditions. Increasing proteolysis favours increased DMS formation in the malt, particularly when induced by higher germination temperatures. The additives gibberellic acid and potassium bromate have opposing effects, some increase being caused by the former and significant reduction being achieved by the latter.     

基于再生水对黄瓜发芽的影响

为评价再生水灌溉对黄瓜作物生长的影响,推动再生水安全灌溉的发展。采用室内研究方法,利用微电脑控制光照培养箱,在25℃黑暗条件下,研究了再生水对黄瓜发芽的影响。结果表明,再生水对黄瓜的发芽势、发芽率和发芽指数的影响与土质和黄瓜品种有关,土培对黄瓜造成的影响较大。建议慎重选择再生水灌溉黄瓜。     

A REASSESSMENT OF THE PATTERN OF ENDOSPERM HYDROLYSIS (MODIFICATION) IN GERMINATED BARLEY

Microscopic and enzymic studies of germinated barley have confirmed that excised barley embryos can produce α-amylase because the peripheral areas of the scutellar tissue contain aleurone cells. In contrast, the aleurone-free tissue of the scutellum is incapable of producing significant quantities of α-amylase. The potential of excised embryos to develop α-amylase is not correlated with the in vivo elongation of the scutellar epithelial cells in the grain because these cells do not elongate in excised embryos. Detailed anatomical studies revealed that the highly insoluble Intermediate layer of cell wall material, which is located between the embryo and the starchy endosperm, is broken-down asymmetrically, thus confirming that enzymic modification of the endosperm is under aleurone rather than scutellar control, in germinated barley. Other studies which have sited the scutellum of barley as inducing symmetric break-down of the endosperm have not linked structural changes, in vivo, with fluorescent or non-fluorescent staining patterns. Some of these studies have failed to recognise the possibility that grains such as sorghum and rice may have a different pattern of endosperm break-down from that of barley.     

几种纳米器件对种子发芽的影响

研究了几种纳米器件处理的活化水对不同种子发芽的影响，探讨了活化水处理时间对种子发芽势、发芽率、发芽指数和活力指数的变化。结果表明，几种纳米器件对水稻浸种均不同程度地提高了种子的发芽势、发芽率、发芽指数和活力指数，对种子的发芽产生了明显影响，在生产中可进一步试验推广应用。     

准噶尔盆地低熟--未熟煤中孢粉与可溶有机质的关系

分析了煤中的孢粉体与可溶于机质关系,认为蕨类孢子含量与氯仿沥青\"A\"和非烃正相关,与饱和烃、芳烃则显著负相关。裸子植物花粉则反之。说明尽管所有生物先质都有生烃作用,但对可溶烃贡献差别较大。而蕨类孢子和裸子植物花粉相比,可能对低熟-未熟油,特别是含非烃较高的低熟油有某种更为密切的联系。后者则与成熟-高成熟煤中才能释放出来的烃类物质更为密切。     

云南烟草种质库种子的生活力监测

【目的】开展烟草种质库资源生活力监测,确保库存资源的安全保存。【方法】选择1979至2008年保存于云南省烟草农业科学研究院种质库的烟草种子;于1992、2005和2019年分别开展3次生活力监测,并统计分析发芽率和发芽势。【结果】种子发芽势和发芽率的年降低值与保存年限有关,保存年限越长,生活力年降低值则越高;而不同年份入库种子生活力下降速率并不一致;种子保存前起始生活力越高,生活力降低越慢。【结论】为了确保烟草种子的长期安全保存,应加强烟草种植过程中田间管理,以及在气象条件较好的天气下收获烟草种子,从而提高种子质量;推荐烟草种质入库发芽率≥90%,但如果条件限制,也不能低于70%;应及时监测预警生活力降至70%的种子,并安排繁殖更新;在烟草种子含水量<5.0%的超干燥和室温的保存条件下,第一次监测间隔不能长于10年,以后每次监测间隔应根据烟草种子生活力下降情况相应缩短。