花榈木实生苗苗期的生长发育节律     

陈志萍  李从瑞  潘德权  邓伦秀 《贵州农业科学》2014,(12)

为花榈木苗木的科学培育管理和培育优质壮苗提供理论依据,利用 Logistic方程拟合方法,对花榈木1年生实生苗木的苗高和地径的年生长发育节律进行了研究。结果表明：花榈木苗木的年生长量呈明显的慢－快－慢－快－慢”的生长发育节律。花榈木生长可划分为出苗期、生长初期、速生期和生长后期4个阶段,出苗期为5月上旬至6月上旬,持续时间长;生长初期为6月中旬,持续时间短,仅10 d;速生期为6月中下旬至8月中下旬,持续时间长,生长量最大,占整个苗高生长量的56．46％、地径生长量的54．69％;地径比苗高提前10 d 进入速生期,持续时间比苗高短22 d,苗高在8月中下旬还有较大生长生,地径在8月中旬提前进入生长后期,苗高持续生长一段时间后在8月下旬进入生长后期。  相似文献   

邓恩桉生材含水率、年轮宽度及木材密度研究     

卢翠香  陈健波  刘媛  周维  毛纯  项东云 《桉树科技》2014,(2):23-27

为了解邓恩桉的木材性质,本研究采用排水法和《GB/T 1930-2009》方法测定邓恩桉的生材含水率、年轮宽度以及木材密度。结果表明：全树生材含水率、年轮宽度、生材密度和基本密度均值分别为114.61%、4.73 mm、1.164 g·cm-3、0.522 g·cm-3。随着树高的增加,年轮宽度、木材密度呈-大-小-大‖趋势,生材含水率呈-小-大-小‖趋势;由髓心向外,木材密度逐渐减小,生材含水率逐渐增大,年轮宽度先增加后减小。4个材性指标在树干径向不同位置间差异极显著,在不同树高间差异不显著（除年轮宽度外）。基本密度与3个材性指标间存在极显著或显著相关。  相似文献   

桂牧1号草地内冬种一年生黑麦草的效果(一)     

闫景彩  黄璜  屠敏仪 《草业科学》2002,19(3):24-26

于深秋至晚春，在桂牧1号草地的行间种植一年生黑麦草，观察测定这种种植方式给2种草及草地带来的影响。试验设计3个处理：①在桂牧1号草地内冬种一年生黑麦草，②单种桂牧1号，③单种一年生黑麦草。把处理②的产草量与处理③的首次产量相加作为处理④，以代表桂牧1号与一年生黑麦草轮作时的产量。结果是：处理①与②中桂牧1号的越冬率无显著差异；处理①的单位面积产草量极显著高于②、④；春季，处理①的杂草极显著地少于②。这表明，在桂牧1号草地内冬种一年生黑麦草是可行可取的。  相似文献   

解放CA10B型汽车功能模型的探讨     

鲍际平  杨永福 《北京林业大学学报》1993,15(2):14-19

本文通过对黑龙江省双丰林业局提供的6台解放CA10B型汽车的使用数据的处理和分析.得出该汽车的单车年周转量及耗油率这两个主要生产参数的影响因素及功能方程.并进一步探讨了该模型对运输企业及木材生产单位的规划、管理、指挥等方面的重要意义.  相似文献   

一年生油松播种苗药物防寒试验     

李国才  王文和  姚清瑞  袁喜财  周宜平  王洪杰  徐桂芬 《内蒙古林业科技》2002,(1):14-15

赤峰市松山区老府林场的一年生油松播种苗越冬时 ,历年都是采取覆土防寒的方法。 1 999年 1 0月苗木越冬前、翌春两次向苗木地上部分喷射不同浓度的自备药物越冬保苗 ,预期达到出圃标准 ,每公顷节省苗木防寒费 45 0元 ,苗木死亡率、损伤率分别降低 3 %、2 %。  相似文献   

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS     

Dong Qiang 《保鲜与加工》1993,(1)

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.  相似文献   

Evaluation of genetic variation among wild rice populations in Cambodia     

Chhourn Orn  Rieko Shishido  Masahiro Akimoto  Ryo Ishikawa  Than Myint Htun  Ken-Ichi Nonomura  Yohei Koide  Men Sarom  Seng Vang  Sakhan Sophany  Ouk Makara  Takashige Ishii 《Breeding Science》2015,65(5):430-437

A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), suggesting that these plants propagate mainly through self-pollination. In the three perennial populations, no individuals had all homozygous genotypes, but redundant genotypes resulted from clonal propagation were observed. Percentages of the redundant genotypes were highly varied (3.6%, 29.2% and 86.0%). This may be due to the different stable levels of environmental conditions. As for chloroplast genome, most of the wild plants showed the same chloroplast types as most Indica-type cultivars have. However, plants with different chloroplast types were maintained, even in the same population. In tropical Asian countries, many wild rice populations were observed under similar ecological conditions examined in this study. Therefore, the present results concerning population structure will be important to further elucidate genetic features of wild rice, and will also give strong clues to utilize and conserve wild natural genetic resources.  相似文献   

不同降雨年型下水分处理对大穗型小麦品种籽粒灌浆及产量的影响   总被引：33，自引：0，他引：33  

冯伟  郭天财李晓朱云集  曹卫星 《水土保持学报》2005,19(1):192-195,199

在大田条件下，探讨了不同降水年型不同水分处理条件下大穗型小麦品种籽粒灌浆及产量的变化。结果表明：通过用不同方程对籽粒生长动态进行拟合，Cubic方程最精确。2000～2001干早年型W和Ws与两个灌浆持续期参数(Se、S)相关性显著．2001～2002丰雨年型W和Ws与3个灌浆速率参数(V、Vs、Vmax)间相关性达显著水平。两年度相比，2000～2001年度籽粒灌浆持续期短，灌浆速率小，导致粒重降低。灌水对灌浆参数的效应年际间存在差异，2000～2001年度随灌水次数增多，S和Se延长，灌浆速率降低；而2001～2002年度随灌水次数增多，S和Se缩短，灌浆速率以灌—水处理最小．灌两水处理最高。灌水对产量的影响，2000～2001年度显著增产，2001～2002年度处理间无显著差异，灌三水处理较灌两水处理反而减产。  相似文献   

Effects of salinity and desalination on seed germination of six annual weed species     

LI Xue-hua JIANG De-ming ZHOU Quan-lai Institute of Applied Ecology  Chinese Academy of Sciences  Shenyang  P. R. China. LI Xiao-lan XIN Jiang Academy of Agricultural  Reclamation Sciences  Shihezi  P. R. China. 《林业研究》2011,(3):475-479

The effects of various salinities and desalination on seed germination of six annual glycophytes (Artemisia sieversiana, A. scoparia, Chloris virgata, Eragrostis pilosa, Chenopodium acuminatum and Chenopodium glaucum) were studied in Horqin Sandy Land, Inner Mongolia, China. NaCl solutions of five concentrations (0 mM, as the control, and 50, 100, 200 and 300 mM) were used for saline stress and desalination treatments. Increasing salinity significantly reduced germination percentages of A. sieversiana, A. scoparia, Ch.virgata and Ch. acuminatum, but had no effect on the germination percentages of E. pilosa. Lower salinity levels (50 mM) significantly increased germination percentage of Ch. glaucum. High salinity might be a precondition for germi- nation after desalination for five of the six species, excepting E. pilosa at NaCl concentration of 300 mM in comparison with non-primed seeds. Higher salinity (>200 mM) led to some specific ion toxicity and reduced seed viability of A. sieversiana. No specific ion toxicity but an osmotic effect limited the germination of other five species was observed The final germination percentages (salinity stress and desalination) of the six species showed three variations in comparison with the controls, namely, indiscrimination, stimulation, and reduction. Germination responses to salinity and desalination suggested that the six species were separated into three categories. Three species (A. sieversiana, Ch. virgata and Ch. acuminatum) showed similar germination responses to salinity with those of halophyte, but also showed a lower tolerance limit than most halophytes, although this was not always the case. A. scoparia and Ch. glaucum exhibited some ’salt stimulation’ in seed germination percentages after desalination, whereas E. pilosa did not show any obvious responseto salinity. Therefore, salinity usually induces dormancy of seeds with strong germination capacity in fresh water, but has few, or even positive, effects on seeds with strong innate dormancy.  相似文献   

Assessment of shoreline vegetation in relation to use by molting black brant Branta bernicla nigricans on the Alaska coastal plain     

Milton W. Weller  K.C. Jensen  Eric J. Taylor  Mark W. Miller  Karen S. Bollinger  Dirk V. Derksen  Daniel Esler  Carl Markon 《Biological conservation》1994,70(3):219-225

To evaluate the importance of large thaw lakes on the Alaska Coastal Plain for molting Pacific black brant Branta bernicla nigricans, distribution and life form of shoreline vegetation were assessed using several scales: satellite imagery, point-intercept transects, cover quadrats, and a parameter for water regime. Brant population and distribution estimates from aerial surveys were used to classify large lakes into high, moderate, and low use. Correlations between brant and abundance of their preferred feeding site — moss flats — were best demostrated by satellite imagery. Intercepts and cover ratings were not correlated, presumably because these techniques were less efficient at assessing area. General observations suggested that the presence of islands, large ice floes, and possibly other physical attributes of the habitat, influenced brant distribution. This area is unique because of low-lying, drained-lake basins that have ideal combinations of moss flats and large water areas where brant seek protection disturbance is vital to the success of this declining species because alternate habitats may not be available elsewhere on the Coastal Plain. in water or on ice floes. Protection of the area from  相似文献