旱作春小麦籽粒形成与灌浆特性

为了给旱地春小麦高产栽培提供依据,对内蒙古赤峰林东旱作地区春小麦籽粒建成及灌浆特性进行了观察和分析。结果表明,籽粒体积和含水量呈单峰曲线变化,籽粒干物质积累量符合“S”型曲线变化。开花后13-27d是小麦籽粒灌浆直线增长阶段,籽粒含水量相对平稳,籽粒重量直线增长,此期干物质积累量的占粒重的78%,为小麦产量形成的关键时期;不同农艺栽培措施对籽粒形成具有显著影响,只有密度适宜,氯、磷、钾三要素适量配施,才能提高灌浆强度,促进籽粒体积增大,增加粒重,获得高产。     

高等植物成花的生理生化与分子机制研究进展

成花过程是高等植物生长发育过程中最重要的阶段之一,包括一系列生理生化代谢与基因调控反应。本文对高等植物成花过程中生理生化与分子机制的研究进行了综述,并介绍了miRNA在植物成花过程中的作用,为成花研究提供参考。     

促进绿色未来的全球木材科学与技术研究进展——国际林联第25届世界大会木材议题综述

国际林业研究组织联盟（IUFRO）第25届世界大会于2019年在巴西召开。文中从木材生长、木材性质与质量、木材识别、木材加工利用和木文化5个方面分别论述了这次大会在木材科学与技术领域的国际最新研究热点与进展,以反映全球木材科学的研究现状,并梳理学科发展方向。木材形成、木材质量、木材高附加值利用、木材识别新技术等议题依然是木材科学与技术领域的未来研究热点。     

Nutrient requirement for zoospore formation in two alariaceous plants Undaria pinnatifida (Harvey) Suringar and Alaria crassifolia Kjellman (Phaeophyceae: Laminariales)

ABSTRACT:   Sporophyll formation in two alariaceous plants, Undaria pinnatifida and Alaria crassifolia , was studied in relation to the nutrient requirements. The sporophylls of U. pinnatifida formed zoosporangia when they had N and P contents greater than 1.4 kgN/m³ and 0.74 kgP/m³. This indicates that these values are the critical nutrient levels for zoospore formation in U. pinnatifida . In the sporophytes of A. crassifolia , many sporophylls with zoosporangia showed nutrient contents higher than 6.25 kgN/m³ and 1.70 kgP/m³. These results suggest that the U. pinnatifida can form zoospores at lower levels of N and P contents than A. crassifolia . Both species often formed zoosporangial sori on the blades in the late period of each reproductive season. The fertile parts of the blade showed N and P contents higher than the critical levels. This phenomenon indicates that the blades have the capability to form zoosporangial sori if there is a sufficient accumulation of nutrients for zoospore formation. The zoospore formation on the blade seems to be accomplished by an overflow of excess nutrients from sporophylls into the blade, or by accumulating sufficient nutrients to form sori even if the sporophylls are not formed.     

一种新的结合SVM和FNN的多聚焦图像融合算法

产业融合共生是新时期红色旅游的必然选择，红色旅游企业共生系统可分为区域内共生子系统和区域外共生子系统，表现为核心共生、主要共生和跨界共生三种形态，核心共生形态是红色旅游企业共生区别其他企业共生的根本所在。红色旅游企业共生由合作和共识耦合而成，但核心共生形态的形成机理更多地表现为天然性，要求红色旅游企业主动寻求合作，争取与其他共生单元达成共识，促进红色旅游企业共生关系的良性发展。     

库木库里沙漠形成时代的初步探讨

本文依据小沙子湖湖积剖面的年代学、沉积学、地球化学与矿物学分析,探讨了湖积剖面的建造与库木库里沙漠发育的关系,认为,在该湖积剖面建造中,沙漠尚未出现,库木库里沙漠的形成在距今6000年前以后。     

苹果砧木M26离体叶片愈伤组织发生及分类研究

对苹果砧木Ｍ２６ 离体叶片愈伤组织的发生研究表明,取继代后３０ ～３５ ｄ 的试管苗顶部１～４ 叶位的叶片,沿与主脉垂直方向横切后,以叶背面朝上方式置于愈伤组织诱导培养基上,经观察在叶片近柄端切口处愈伤组织发生较早,产生量较多。最适的愈伤组织诱导培养基为：ＭＳ＋２ ,４ － Ｄ０ ．２ ～２ ．０ ｍｇ·ｌ－ １ ＋ＩＡＡ０ ．２ ～２．０ ｍｇ·ｌ－ １ ＋ ＢＡ０ ．５ ～１．０ ｍｇ·ｌ－ １ ＋ 蔗糖３ ％ ＋ 琼脂０．６％ 。将诱导产生的愈伤组织按外部形态、细胞特点及生理生化指标等分为三类,其中表面干燥致密、细胞内含物丰富、淀粉、蛋白质及干物质含量均较高的Ⅲ类愈伤组织的芽再生频率最高,可达８３ ．３３ ％ ,是能利用的愈伤组织类型。     

早熟和特早熟桃胚珠培养研究

本文以自然授粉的‘春蕾’、‘沪017’、‘布目早生’、‘1-4-8’、‘7-6-9’的胚珠为试材,研究了早熟和特早熟桃胚珠培养胚成苗的有关影响因素。本试验5个品种(品系)的结果表明,桃品种或品系的果实生育期愈短,胚珠培养胚的成苗率愈高,特早熟桃‘春蕾’花后48天的胚珠培养在改良S H培养基附加BA1.0mg/1 IAA1.0mg/1上30天,将长大的幼胚转移至TM培养基上,胚的成苗率达75％。此外,作者对胚珠培养技术在桃育种中的应用范围及其培养程序开展了讨论。     

Comparative Studies on Corynebacter1Um Pyogenes Toxin Formation in Monocultures and Mixed Cultures: The Demonstration of a Stimulating Effect of Peptococcus Indolicus and Stuart-Schwan Cocci

The growth and the toxin (i.e. hemolysin) producing capacity of Corynebacterium pyogenes were studied in monocultures and in co-cultures with 1 or more of the organisms frequently accompanying it in summer mastitis in cattle (Peptococcus indolicus, Stuart-Schwan cocci, Bacteroides melaninogenicus subsp. levii, Fusobacterium necrophorum and Streptococcus dysgalactiae) or with organisms seldom associated with summer mastitis (Streptococcus uberis, Streptococcus agalactiae, non-toxic staphylococci and Escherichia coli).Pc. indolicus, and to some extent also Stuart-Schwan cocci, stimulated the growth as well as the hemolysin producing capacity of Gb. pyogenes (Table 1) while Str. dysgalactiae, Str. uberis, Str. agalactiae, E. coli and the majority of the staphylococci reduced these activities. Most F. necrophorum strains stimulated the growth, but not the hemolytic activity. With B. melaninogenicus the results were inconclusive.The effect of Pc. indolicus appeared to be associated with the production of a filterable factor (Tables 2 and 3).Mouse toxicity and hemolytic activity of culture filtrates were closely correlated (Table 4).     

论七体的形成和演进

七体是赋的分支 ,具有与其它赋类相区别的特点 ,其基本体制由西汉枚乘《七发》确立。七体在其流变过程中 ,招隐取代问疾成为题材上的突破 ,仕隐之辩为文人表述个人情性、价值取舍及德政标准提供了合适的途径。结构形式和语言运用上的创新也显示了作者们不囿于前人的努力