Effect of applying nitrogen fertilizer to a potato seed crop on the susceptibility of the daughter plants toErwinia carotovora subsp.atroseptica

Summary Seed potatoes of cvs Record and Bintje were grown with 30, 80 or 130 kg N/ha. In the subsequent growing season the seed tubers, which were inoculated or not with two concentrations ofErwinia carotovora subsp.atroseptica (Eca), were subjected to the same fertilization treatment. The incidence of blackleg and the level of seed tuber decay increased from the uninoculated treatment to the higher inoculum level, but the degree varied considerably from one year to another. Cv. Bintje was more susceptible to blackleg and yield loss caused by Eca than cv. Record. In 1990, when disease incidence was high, the proportion of blackleg stems increased with increasing doses of nitrogen fertilizer which had been applied to the seed crop, but was not significantly affected in 1988 and 1992. Seed tuber decay was retarded by the lowest nitrogen dose. The yield of the subsequent crop was not affected by the nitrogen dose applied to the seed crop.     

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。     

陇东黄土高原地表粗糙度对耕作土壤径流的影响

用人工模拟降雨器,对陇东黄土高原不同地表粗糙度(RR)条件下翻耕土壤的径流和蓄水能力进行研究.以兰州大学庆阳黄土高原试验站为试验点,设3个处理:轻度(LR,RR＝7.6 mm),中度(MR,RR＝10.1 mm)和重度(HR,RR＝21.0 mm)处理.结果表明:在66mm/h的降雨强度下,降雨开始的20min内,LR...     

四合木种子特性的测定研究

本文就蒺藜科的四合木种子进行了千粒重，吸水增重率，发芽率，生活力，活力五项测定，并分析了测定结果与方法，得出了很有价值的结论。     

超干燥和低温贮藏对华北驼绒藜种子劣变及同工酶的影响

华北驼绒藜种子在超干燥（含水量4．2％～4．5％）室外温度条件下贮藏,与低温贮藏效果基本相同,能显著延长种子寿命。在超干燥贮藏过程中,种子的同工酶（超氧化物歧化酶、过氧化物酶、酯酶）系统的活性均明显高于对照,结果延缓了种子老化,从而提高了其贮藏寿命。     

浑善达克沙地药用种子植物区系分析

本文应用植物区系地理学的基本原理,对浑善达克沙地药用种子植物的科、属组成和属的地理成分进行了统计分析,结果表明:(1)本区有药用种子植物78科,270属,504种。(2)优势科现象明显;单种属、寡种属数量最多,属级水平的多样性丰富。(3)该区系包含14个分布区类型,温带性质的成分占绝对优势,热带性质的成分不多,特有程度低。(4)资源区域间分布差异大;有一定的古老成分。     

Factors affecting seed germination and emergence of Gomphrena perennis

Controlled growth chamber experiments were conducted to determine factors affecting seed germination and emergence of the troublesome weed Gomphrena perennis. The objective of this research was to examine the effects of temperature, light, moist chilling, osmotic potential, dry storage and depth of seed burial on G. perennis germination and emergence. The optimum temperature for germination was around 15–20°C. Seeds showed germination rates above 90% under 20/10 and 25/15°C temperature regimes. The minimum exposure to light needed to stimulate germination was 1 min. However, the light requirement was reduced after a long storage period. Furthermore, germination was high (>90%) in all moist‐chilling treatments tested. Germination was highly sensitive to increasing osmotic stress. The highest germination percentage (94%) was achieved at 0 MPa, and decreasing osmotic potential from 0 to ?0.3 MPa reduced germination to 11%. The highest seedling emergence occurred for seeds placed from 0 to 1 cm deep, and no seedlings emerged from a 5‐cm burial depth. Gomphrena perennis has a suitable environment in a no‐till soybean field, where seeds remaining on the surface have the required temperature, light and depth needed for germination.     

香型优质高产杂交稻国豪国香8号高产制种技术研究

[目的]推广应用国豪国香8号。[方法]对国豪国香8号的特征特性及其制种技术进行阐述。[结果]国豪国香8号具有米质优、口感好、抗性较强、制种产量高等特点,3年区试生产试验平均产量比汕优63增产了3.30%、1.60%和9.60%。[结论]制种时花期应避开高温伏旱,严格隔离条件,确保种子质量。     

不同贮藏条件下白术种子蛋白质含量的研究

将不同含水量的白术种子放在不同温度条件下贮藏1a，测定种子内蛋白质含量。结果表明：较低含水量的种子在较低温度下贮藏，白术种子的蛋白质含量较高。随着贮藏温度和种子含水量的增加，种子中蛋白质含量表现出下降的趋势。而且含水量对种子中蛋白质含量的影响较温度更为明显。     

基于TDLAS的储粮二氧化碳激光检测系统研制

储粮过程由微生物及害虫等组成的生物场与温度和湿度等构成的非生物场所造成的影响会降低粮食品质,影响粮食安全。储粮中二氧化碳浓度反应粮库生物场状况,是储粮生物场监测的重要指标。为实现储粮二氧化碳浓度高精度检测,该研究基于可调谐半导体激光吸收光谱(Tunable Diode Laser Absorption Spectroscopy,TDLAS)技术高灵敏度和快速响应的特点研制了一套储粮二氧化碳浓度现场检测系统,并建立了二氧化碳激光光谱分析与数据处理方法。基于便携式要求,系统采用紧凑型设计,集二氧化碳浓度、温度及湿度检测功能于一体,同时实现弱信号调理、二氧化碳浓度计算及生成多参数云图、水势图显示等功能。整机尺寸338 mm×251 mm×88 mm,室温条件下功耗小于1.3 W。试验结果显示：该检测系统能够长时间稳定工作,人机交互功能鲁棒性较好,对储粮二氧化碳浓度检测的响应时间小于20 s,线性误差小于1.2%,检测重复性为0.4%,检测精度为10mg/m³,检测范围为0～20 000 mg/m³,温度的检测范围为-40～120℃,湿度检测范围为0...