粗腿羊肚菌子囊孢子萌发过程及其细胞核行为

用4μg/mL 4′,6-二脒基-2-苯基吲哚(DAPI)对细胞核染色,采用激光共聚焦显微成像技术观察粗腿羊肚菌(Morchella crassipes)子囊孢子的萌发过程。新鲜的粗腿羊肚菌子囊孢子呈椭圆状,大小13.0~15.3μm×21.5~24.0μm,成熟子囊孢子的细胞核数量为18~32个;CYM液体培养基,23℃培养6h后子囊孢子体积逐渐膨大至初始体积的1.7~2.9倍,泡囊化现象明显;6~12h开始形成芽管,泡囊逐渐消失,出芽点在椭圆形细胞的一端形成或两端先后形成,数量不等的细胞核由子囊孢子内迁至芽管中,形成多核丝状;芽管生长至20~30μm后,在出芽点与孢子连接处形成隔膜,12~24h后,随着芽管的持续生长,形成新的隔膜和菌丝细胞,菌丝细胞多核;芽管及初生菌丝直径6~8μm,约为子囊孢子直径的1/3;24h内没有观察到初生菌丝之间发生细胞融合现象。     

Seed viability determination in parasitic broomrapes (Orobanche and Phelipanche) using fluorescein diacetate staining

Fluorescein diacetate (FDA) was investigated as a potential viability stain for seeds of holoparasitic broomrapes Orobanche and Phelipanche (Orobanchaceae), using four weedy and two non-weedy taxa. FDA viabilities were compared with the currently used 2,3,5-triphenyl tetrazolium chloride (TTC) test, and in vitro germination induced by the strigolactone analogue GR-24. Viable FDA-stained seeds were characterised by bright yellow–green fluorescence under 450–490 nm blue light. These viable seeds could be discriminated from non-viable seeds, in which low levels of fluorescence, similar to non-stained control seeds were observed. FDA viabilities were not significantly different from those obtained using the TTC stain; however, viability values for both stains were consistently higher than levels of artificially induced germination. Positive TTC-staining showed continuous variation that was difficult to interpret. Nevertheless, the TTC test does not involve grinding seeds, and therefore probably remains a practical alternative to FDA for screening soil samples contaminated with Orobanche and Phelipanche seeds, which indicates different applications for the two viability tests. Interestingly, the strigolactone analogue GR-24 only induced germination in O. crenata , P. ramosa and O. minor , suggesting a high specificity towards this germination inducer among the species investigated. We suggest that FDA-staining provides a potential alternative to the currently used TTC test for seed viability assays for Orobanche and Phelipanche , and other parasitic weeds which are an obstacle to crop cultivation.     

温度与土壤水分对玉米种子萌发及幼苗生长特性的影响

以沈单16、豫玉22为试验材料,研究不同温度、土壤水分对玉米种子萌发及幼苗生长特性的影响.结果表明,随温度与土壤水分的下降种子发芽势、发芽率均呈降低趋势.温度与土壤水分对幼苗生长各指标的影响不同,玉米芽鞘长、幼苗长、贮藏物质转运率和叶绿素含量均随温度与土壤含水量的降低而减小;过氧化物酶活性、脯氨酸含量呈先增加后降低的趋势.在环境温度低于15℃恒温条件下,玉米种子发芽率迅速降低,土壤含水量低于10％时种子不能正常萌发;在15℃及以下低温,土壤含水量低于10％时玉米幼苗生长受到抑制.持续性低温、干旱胁迫不利于玉米种子的正常萌发与幼苗的生长.     

水稻花粉的离体萌发

选出适合于水稻花粉萌发的液体培养基： 20%蔗糖+10%PEG4000+40 mg.L-1H3BO3+3m mol/L Ca(NO3)2+10 mg.L-1VB1, 得到80%的萌发频率。 离体萌发时, 花粉管生长很快, 在30 min内可达700 μm。 最适萌发的温度范围较宽, 27～33℃都可以得到较高的萌发频率。     

不同药剂浸泡处理对山桃稠李种子发芽的影响

为了促进山桃稠李种子萌发,提高山桃稠李种子繁殖的发芽率,以清水作为对照,采用不同浓度的高锰酸钾、过氧化氢、赤霉素对山桃稠李种子进行处理,比较不同药剂、不同浓度及不同处理时间对山桃稠李种子发芽的影响。结果表明:不同药剂处理的种子发芽率有显著差异,不同处理时间之间没有显著差异,各药剂处理按照发芽率由高到低的顺序排列依次为高锰酸钾、赤霉素、过氧化氢、水处理。对发芽促进效果最佳的组合是0.7%的高锰酸钾浸泡处理48h,发芽率可达88%。     

A longitudinal examination of business performance indicators for drought-affected farms

Frequent severe droughts can financially cripple dryland farm businesses and farmers need effective business strategies to survive. This study analysed the economic performance of 123 farms in a rainfed agricultural region of Australia from 2004 to 2009, a period that included severe droughts in 2006 and 2007. The business indicators examined were business equity, operating profit/ha, return on capital, and the debt to income ratio and the droughts altered these indicators for many of the farms surveyed. Over the study period the equity position of just over 60% of farms declined, although 55% of these had more than 80% equity in the business initially and were able to absorb a short term decline in equity caused by the drought. In addition, 9% of farms had levels of equity below 80% at the start of the investigation, but actually improved their equity position by the end of the study. Strong links were found between wheat yield and the business indicators. Mostly this was due to the crop dominant nature of the farm businesses where wheat was by far the main crop. However, farms that were able to capitalise on favourable conditions in other years were better placed to enhance or recover their financial position. Farms that cropped a higher proportion of their farm area were at an advantage. Structural indicators, including the percentage of area cropped, had a small but significant effect on the debt to income ratio, the return on capital and operating profit. Farm diversity also favourably lessened the debt to income ratio. Other factors, including farm size did not influence the outcome of any business indicator. Farms that remained resilient, despite the serious droughts were those that cropped more than 50% of their farm area, were prudent in their expenditure, maintained some enterprise diversity and often generated wheat yields in each year that were near the yield potential for that year.     

Pod, Seed and Germination Characteristics of Selected Cardamom (Elettaria cardamomum (Linn.) Maton) Varieties

Cardamom is a popular and important tropical spice, traditionally propagated by rhizomes, although seeds which are considered recalcitrant are being increasingly used in planting programmes. Thus a study evaluated the effects of pod maturity on pod, seed and germination characteristics of three popular varieties, along with the influence of drying on seed germinability.
Green and yellow mature pods and seeds of all varieties had a high moisture content. The variety Mysore, which is considered high yielding, had larger pods with a greater number of heavy seeds. Although the pods of Vazukka were heavier than the Malabar variety due to greater seed weights, seed numbers were similar in both varieties. Seed moisture contents declined with increasing pod maturity, while seed weights and germinability increased.
The germinability of Mysore seeds were greater, while that of the other varieties were lower. The larger seeds of all varieties germinated 15–20 days earlier, giving rise to a greater percentage (20–25 %) of seedlings. Desiccation at 20 °C maintained germinability for a longer period (5–9 days) in all varieties, than when dried at 30 °C. The seeds of the variety Mysore was more tolerant to desiccation than other varieties. The study illustrated the importance of selecting large seeds from yellow mature pods of cardamom for propagation and the value of establishment immediately after harvest to obtain a greater number of seedlings.     

披碱草野生种质材料芽期耐盐性研究

通过对20份来自不同地区的披碱草野生种质材料在0、0.4%、0.6%、0.8%、1.0%浓度盐胁迫下的相对发芽率、相对发芽势、致死浓度等指标的综合评价,筛选出耐盐材料4份(G8、G17、G18、G19),分别来自甘肃古浪县、山西沁源、甘肃古浪县、山西五台山;敏盐材料3份(G2、G3、G5),分别来自北京百花山、北京灵山、新疆吉阜康白杨沟;其他为中等耐盐材料。     

芳香植物种子的萌发试验

[目的]探讨不同栽培基质和植物生长调节剂对芳香植物种子萌发的影响。[方法]以普罗旺斯薰衣草、法国百里香和柠檬草薄荷为试验材料,研究园表土、营养土＋砂以及营养土＋陶粒3种不同栽培基质,以及GA3和6-BA2种生长调节剂对种子萌发的影响。[结果]3种芳香植物种子在营养土＋陶粒的栽培基质中萌发较好;GA3和6-BA对3种芳香植物种子的萌发都有促进作用,且GA3的促进作用较为明显。[结论]芳香植物用GA3处理并在营养土＋陶粒的栽培基质中培育效果较好。     

影响罗布麻种子萌发的因素研究

对不同年限吉林红麻进行不同温度、湿度、土壤肥力以及存放条件的相关研究。结果表明:种子萌发率与种子保存时间呈负相关,高温处理罗布麻种子能使其萌发率达到最高,育种土掺入30%的鹿粪可大大增加罗布麻种子发芽率,湿度对罗布麻种子的萌发影响不显著。由此可得出有利于罗布麻种子萌发的最佳因素,促进有性繁殖技术的提高。为日后规范化栽培提供重要依据。