氮,磷肥和灌水对小麦黑胚病发生的影响

在田间人工接种条件下，研究了氮肥、磷肥和灌水对小麦黑胚病发生的影响。结果表明，氮肥（尿素）和氮肥十磷肥（过磷酸钙）混施可降低小麦黑胚病粒率，单施磷肥的作用不明显；少２次灌水对黑胚病发生亦没有明显影响。因此，建议生产上增施氮肥以减轻小麦黑胚病发生和危害。     

无籽西瓜新品种津蜜20的选育

津蜜20是天津科润蔬菜研究所新育成的黑皮、大果无籽西瓜新品种。全生育期110d,果实发育期35d。植株生长旺,叶柄短,抗病性强。果实圆球形,耐贮运,瓤色大红,品质优,中心可溶性固形含量平均12%以上。单果重5-7kg,667m2产量3500kg以上。抗西瓜枯萎病。     

四川亚高山暗针叶林的起源及其基本特征的研究

本文根据古地理变迁和古植物资源，应用多学科观点和理论，对四川暗针叶林起源的时代、来源，扩展以及四川暗针叶林的基本特征进行了系统的分析和论述，进一步阐明了四川暗针叶林本地起源的观点，同时分析指出生态因子的骤变和补偿作用，是促进四川暗针叶林形成、发展和繁荣的重要原因。     

Factors Causing the Variation in the Temperature Coefficient of Dark Respiration in Rice (Oryza sativa L.)

Abstract

The temperature coefficient (Q₁₀) of dark respiration in rice gradually decreased in continuous darkness, fluctuating as the circadian rhythmic variation in dark respiration. The solar radiation (MJ m^-2) on the day of measurement and the nitrogen concentration in the culture solution hardly affected the Q₁₀ value. However, the plants exposed to high-intensity light (260W m^-2) for two weeks showed a higher Q₁₀ of dark respiration than those exposed to low-intensity light (70W m^-2). The seasonal variation in Q₁₀ value was not observed. The average Q₁₀ value during the growth stage measured at 15 to 25°C, 20 to 30°C, and 25 to 35°C was 2.14, 1.76, and 1.56, respectively. High crop yield in the regions where the day/night temperature difference is large may be partly explained by the high Q₁₀ at low night temperature. Thus, the Q₁₀ may be an important physiological factor determining high crop yield.     

Exudates of dark septate endophyte (DSE) modulate the development of the arbuscular mycorrhizal fungus (AMF) Gigaspora rosea

Exudates of a dark septate endophyte (DSE) identified as Dreschlera sp., a common endophyte isolated by the inner cortical cells of the grass Lolium multiflorum, were put in contact with the arbuscular mycorrhizal fungus (AMF) Gigaspora rosea. These exudates stimulated the hyphal length and the hyphal branching of the AMF. A negative effect on the extramatrical phase of the AMF was detected. This is the first report to show how exudates of DSE can affect the development of AMF. These results show that DSE could be modifying the mycorrhizal status of the plants, modulating a different symbiosis in the rhizosphere.     

我国石榴的研究开发现状及发展展望

近年来,石榴因其在食用、药用、观赏、绿化、工业等方面的迅速发展而引起了人们的广泛关注。分别对石榴根、石榴叶、石榴皮、石榴汁、石榴籽的研究开发现状进行分析总结,并对石榴未来发展的前景作出展望,旨在为我国石榴研究开发和产业化发展提供参考。     

低磷胁迫对晒红烟内源激素和根系活力的影响

通过盆栽试验和室内分析,研究低磷胁迫对晒红烟内源激素和根系活力的影响。结果表明,低磷胁迫下晒红烟的根系活力活性降低,根冠比及根和叶中生长素(IAA)含量均增加,干物质积累和细胞分裂素(ZR)含量则减少。低磷胁迫下,烟株为适应胁迫环境,IAA/ZR比值增大,促进了根系发育,使根冠比增大,以提高对磷的吸收效率,用来满足烟株对磷素的需求。     

黑皮大果无籽西瓜新品种郑抗无籽5号的选育

郑抗无籽5号是以MMD为母本,D106为父本杂交育成的新品种。该品种中晚熟,果实发育期36-39d。生长势较强,抗病耐湿,易坐果,单果重6-8kg,普通栽培667m2产量4500kg左右。果实圆球形,黑皮,覆蜡粉,外形美观;瓜瓤鲜红色,中心可溶性固形物含量12%以上;瓤质硬脆,白秕籽小、少,汁液多,风味正,品质优。果实整齐度好,商品果率高,极耐贮运。该品种适应性强,全国各地均可栽培。已在全国15个省示范推广逾1.2万hm2。     

Agricultural management affects communities of culturable root-endophytic fungi in temperate grasslands

Three grassland sites of similar physical characteristics but differing management histories were chosen to test the hypothesis that agricultural disturbance has a deleterious effect on the diversity of culturable root-endophytic fungi and favours potentially pathogenic species. Species abundance data were collected for fungi isolated from surface sterilised root samples. Brillouin index of diversity, Twinspan and detrended correspondence analysis were applied to the community data. Quantitative ordination separated the samples by site showing that the communities differed in fields of contrasting management and this was supported by data from a microcosm experiment. Species presence and absence appeared to be affected seasonally; site differences were manifested in relative abundance. Diversity did not appear to vary by site, but a methodological explanation for this is proposed. Sterile dark septate endophytes were shown to be among the most abundant groups at all sites.     

避光预处理和营养液栽培对水仙观赏价值的影响

试验探讨不同处理营养液栽培对水仙观赏品质的影响,为实际生产提供参考.试验方法是采用清水栽培、不避光预处理霍格兰溶液栽培为双对照,避光预处理7 d后用霍格兰溶液培养中国水仙,结果显示:处理水仙植株根系健壮、嫩白,叶片鲜绿厚实,根长/根径比及叶长/叶宽度比明显减小,与不避光预处理霍格兰溶液培养差异显著(P<0.05),与清水对照之间有极显著的差异(P<0.01),花梗数、每梗花朵数、花冠外径、花期与不避光处理营养液栽培对照无差异(P＞0.05),与清水对照之间都有极显著的差异(P<0.01),花期延长4 d左右;观赏价值明显提高.