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1.
基于远缘杂交技术路线,以中国沙棘优良单株MK-88-01、HF-88-05为母本,俄罗斯栽培种阿列依及蒙古大果沙棘乌兰格木子代优良雄株为父本,开展了中国沙棘与蒙古沙棘2个亚种间杂交育种研究。结果发现:杂种子代性状分化严重,棘刺数、百果质量、果实产量等最重要的几项经济指标的遗传分化程度最大。选育出3个优良杂种单株,其树高均显著高于父本,2年生枝棘刺数均为3个,与母本中国沙棘相比,棘刺数大量减少。优良杂种单株百果质量与单株产量分别达26.33 29.33 g、2.00 2.50 kg,比母本中国沙棘分别提高31.34%46.30%、66.67%108.33%。杂交子代具有单株生长量越大,其果实与种子表型指标就越小的变化规律,与母本中国沙棘体大果小、父本蒙古沙棘体小果大的表型特征相吻合。  相似文献   

2.
桉树幼苗菌根接种及其生长效应的研究*   总被引:5,自引:4,他引:5       下载免费PDF全文
  相似文献   

3.
探究高场强微波处理过程中,樟子松试材含水率、微波功率、处理时间对试材吸收微波能量和宏观裂纹的影响。结果表明,试材处理前的含水率、微波功率对试材吸收的微波能量有显著影响;当含水率为40%~60%、微波功率为140 kW、处理时间为120 s时,樟子松试材横截面的裂纹面积比和裂纹数量最大。建议根据功能化材料的应用领域,选择不同的微波处理工艺。  相似文献   

4.
薄壳山核桃品种果质性状变异及选择改良研究   总被引:3,自引:0,他引:3  
对南京地区引种的21个薄壳山核桃品种果实单果重、出仁率、出油率,果型指数性状进行测定分析.结果表明,各性状均有显著的遗传变异,具有明显的改良潜力.相关分析未发现性状间有相互制约的关系.通过综合性状改良,由综合坐标评定法选出Mahan,Wictita,Sioux,Pawnee,Elliott,Shawnee等6个优良新品...  相似文献   

5.
张海旺 《林业科技》2020,45(2):32-35
以6年生‘燕红’和‘沙红’桃树为试材,调查冬季桃树修剪前后枝量、修剪量、夏剪量,统计分析了其与产量之间的关系。结果表明,在一定的区间内,燕红和沙红的产量随着修剪率和留枝量的升高呈现先升高后降低的趋势,在修剪率为34.63%、43.37%时,产量达到最高,为17.81、7.17 kg;留枝量为134、110时,产量达到最高,为20.58、7.04 kg;长枝率为14.14%、27.35%时,燕红和沙红产量最高,为19.94、7.04 kg;燕红和沙红的产量随着中短枝率的升高整体呈现先降后升的趋势,在中短枝率为59.56%、54.36%时,产量达到最低,为14.20、4.18 kg。通过回归分析得出,燕红和沙红产量与修剪率(燕红17.89%~59.03%、沙红18.90%~62.34%)、留枝量(燕红:94~185个、沙红:73~146个)均呈二次项回归模型;燕红产量与长枝率无相关关系,沙红产量与长枝率(4.61%~27.35%)呈线性关系;燕红、沙红产量与中短枝率(燕红43.28%~73.06%、沙红39.22%~69.58%)呈二次项回归模型。  相似文献   

6.
对江西省16个1年生和10个2年生油茶苗圃进行调查,结果表明,1年生和2年生大田嫁接苗的平均合格率分别为48.0%和76.6%;2年生苗的合格率与土壤有机质和水解氮的含量正相关。2年生苗推荐的施肥水平为:土壤全氮0.114%~0.413%、水解氮114.86~132.92 mg/kg、全磷0.047%~0.073%、速效磷32.13~71.59 mg/kg、全钾1.203%~1.274%、速效钾48.08~67.08 mg/kg、有机质2.627%~3.171%。  相似文献   

7.
A landscape model (LANDIS) was used to study the long-term forest dynamics under five planting types (100% larch (P1); 70% larch and 30% Mongolian Scotch pine (Pinus sylvestris var. mongolica) (P2); 50% larch and 50% Mongolian Scotch pine (P3); 30% larch and 70% Mongolian Scotch pine (P4); 100% Mongolian Scotch pine (P5)), which were also employed in severely burned area under current planting intensity, and under natural regeneration (as a comparison) in Tuqiang Forest Bureau in the northern slopes of Great Xing’an Mountains after the catastrophic fire in 1987. Results showed that different planting types had a significant influence on the abundance of larch, Mongolian Scotch pine and white birch. The abundance of larch increased with time, whereas the abundance of Mongolian Scotch pine was in a converse way. The abundance of larch and Mongolian Scotch pine under these planting scenarios was higher than that under natural regeneration. Under these planting scenarios, the abundance of larch increased with the increasing proportion of larch, and the abundance of Mongolian Scotch pine was in a similar way. Contrary to larch and Mongolian Scotch pine, white birch had higher abundance under natural regeneration than that under these planting scenarios. Also, the different proportions of larch and Mongolian Scotch pine had an influence on the abundance of white birch. White birch had higher abundance with the increasing proportion of Mongolian Scotch pine. As for the total abundance of larch and Mongolian Scotch pine, the difference was not significant under P2, P3 and P4 scenarios, but was higher than that under P1 and P5 scenarios, which indicated that individual-species planting should not be used in the forest landscape. __________ Translated from Chinese Journal of Applied Ecology, 2006, 17(5): 855–861 [译自: 应用生态学报]  相似文献   

8.
樟子松人工林下针阔叶凋落物分解动态   总被引:32,自引:3,他引:32  
沈海龙  沈国舫 《林业科学》1996,32(5):393-402
实验在位于张广才岭西坡的东北林业大学帽儿山实验林场老山人工林实验站进行。结果如下,樟子松枯叶在凋落后第1年和第3年的失重率分别34.67%和63.75%,樟子松枯落球果、树皮和树枝在凋落后第1年的失重率仅为枯叶的36.69%、33.66%和30.12%;红松、柞树、榆树和水曲柳枯叶在凋落后第1年和第3年的干物质失重率分别为樟子松枯叶的58.70%和84.71%、81.6%和80.55%、134.94%和156.55%及124.26%和147.71%。凋落后第1年的干物质失重量达总凋落量的26.61%,其中占总凋落量的11.85%阔叶树枯叶的失重量达总失重量的20.51%;占总凋落量43.64%的樟子松枯叶的失重易达总失重量的58.29%;而占总凋落量24.28%、13.10%和6.89%的樟子松柏树皮、枯树皮和枯球果分别仅提供10.92%、5.28%和3.37%的失重量、不同枯落物的营养元素净释放率和释放量的实验分析结果表明,凋叶树枯叶在林地地力维持中起重大作用。  相似文献   

9.
An analysis of the seasonal cycle of growth and reproduction of the field vole in southern Bavaria in the years 1972, 74 and 75 showed a turnover of development in midsummer indicated by reduced weight increase, restricted reproduction and low fertility. Highest weight increase of 436 marked and recaptured specimens in the field was observed during May and June with 269 mg (335 mg males, 188 mg females) per day and individual (Abb. 1). During August and September a mean weight decrease of –82 mg per animal was measured. The daily weight increase per individual reached 67 mg (74 mg males, 54 mg females) in the average of all observed years.An autopsy of 220 snap-trapped specimens showed a significantly reduced weight of testes (–86%), of stomach content (–22%) and of liver (–18%) in late summer compared to the weight in spring when growth and reproduction were highest and these organ weights reached the maximum level. In the summer crisis also some blood parameters showed significant changes. The erythrocyte counts were reduced by –34% hemoglobin content by –24%, hematocrit by –7%, glucose concentration by –80% and lipid content by –33% in comparison to the mean values observed in December and January when these parameters reached the maximum level. However the spleen size was increased by 140% and the leucocyte counts were augmented by 234% in late summer.A complex of factors influencing the summer crisis of the field vole such as detioration of food supply, increased parasite attack especially of Babesiosis and hormonal changes of growth potencie during the seasonal cycle of development were discussed.

Mit 6 Abbildungen  相似文献   

10.
The effects of Butea superba on the reproductive system in male Wistar rats were investigated. The animals were fed daily with the powdered crude drug suspended in distilled water by a gastric tube at the dose of 2, 25, 250 and 1250 mg/kg body weight for 8 weeks. Rats fed with 1 ml of distilled water were used as a negative control. The weights of all vital organs in all treated groups were not different from the control. The percentage weight ratios of body weights of seminal vesicles and prostate glands were not different from the control, except that the testis of the group fed with 1250 mg/kg was significantly different from the control and the other treated groups. In addition, the sperm counts in this group showed about 16% more than the control group. Hematology as well as the liver and kidney function of all treated groups showed no difference from the control. B. superba, drug at 250 mg/kg which was 100 times more than the Thai FDA recommended dose for humans appeared to be safe in rats. The crude drug has demonstrated an increase tendency on testis weight and sperm counts in rat. The information from the present study can be used to explain the Thai folklore application of this plant in Thailand.  相似文献   

11.
1982年以来在湖南省汉寿进行了Ⅰ-69杨人工林生长规律与营养特性的定位研究。前三年(1982~1984年)结果表明,当地的气候、土壤生态因子适于Ⅰ-69杨生长,胸径生长年、月变异极显著。第一年生长慢,8月为高峰期;第三年较第二年次之,6月为高峰期。三年胸径年平均增长4.78 cm。主要营养元素(除Mg外)的月变异极显著,与胸径生长规律一致。年变化无显著差异,年平均含量较高,N为3.25%~3.31%,P_2O_5为0.58%~0.59%,K_2O为1.59%~1.61%,CaO为3.17%~3.28%,MgO为0.54%~0.70%,反映了Ⅰ-69杨生长与主要营养元素吸收、利用以及土壤养分的供给,处于动态平衡的良好状态。  相似文献   

12.
13.
应用印楝素乳油进行了松毛虫、松小蠹的室内防治效果试验。试验结果表明用 0 3%印楝素乳油 4 0 0倍“触杀 +胃毒”处理松毛虫 ,施药后 2 0天 ,防治效果达到 88 5 % ;用 0 3%印楝素乳油 10 0倍“触杀 +胃毒 +内吸”处理松小蠹 ,施药后 15天 ,防治效果达到 95 6 %。观察发现 ,施用印楝素后 ,使松毛虫 2龄幼虫产生较强的拒食作用 ,并能抑制其生理发育。  相似文献   

14.
云南镇雄核桃优良单株选择初报   总被引:1,自引:0,他引:1  
2007年以来,对云南省镇雄县核桃进行选优调查,预选优株143株,复选优株67株,按照国家标准,决选优株7株,其中乌蒙123号、105号、127号、108号、124号、110号丰产性能优于国家标准,109号稍低于国家标准.评选出的7株优良单株,其坚果粒重为9.07~11.40 g,壳厚为0.80~1.10 mm,出仁率...  相似文献   

15.
利用东北林区云冷杉林、落叶松林、樟子松林、红松林、栎树林、桦树林、杨树林、榆树林、椴树林和水胡黄林10种森林类型的1947个样地的激光雷达数据和地面实测蓄积量数据,首先通过多元线性回归和非线性回归方法,分别建立基于机载激光雷达数据的森林蓄积量回归估计模型,并通过对比分析,确定统一形式的基础回归模型;然后利用哑变量建模方法,建立基于不同森林类型参数和相同激光雷达变量的蓄积量模型。结果表明,研究建立的10种森林类型的线性蓄积量回归模型的解释变量个数在2~7之间,确定系数在0.460~0.858之间;非线性蓄积量回归模型的解释变量个数在2~4之间,确定系数在0.461~0.846之间。基于点云平均高度和平均强度建立的10种森林类型的二元蓄积量模型(研究称之为标准模型),其确定系数在0.440~0.815之间,平均预估误差在2.88%~4.42%之间,平均百分标准误差在16.76%~25.52%之间,预估精度基本达到森林资源规划设计调查技术规定要求。依据研究建立的10种森林类型的蓄积量模型,可以编制基于激光雷达数据的航空林分材积表,在森林资源调查实践中推广应用。  相似文献   

16.
光肩星天牛危害对杨树损失的研究*   总被引:7,自引:0,他引:7       下载免费PDF全文
  相似文献   

17.
通过对金华、绍兴2个薄壳山核桃种10多年引种调查认为:薄壳山核桃2年生苗移栽后,4~7 a进入结实期,10 a后进入大量结实期,其中:金华13年生最高株产16 kg;果形大,种实单粒重6.5~9.4 g,种壳厚0.9~1.1 mm,出仁率51%~56.9%,粗脂肪76.9%~78.5%,蛋白质8.5%~9.7%,可作为主栽品种发展。绍兴13年生最高株产14.6 kg,平均7 kg;单果较小,核果重5.5~6.3 g,核壳厚1.1~1.2 mm,出仁率52%~53.8%,种仁饱满,粗脂肪74.1%~74.4%,蛋白质7.5%~8.3%,可为供种或授粉树适当发展。上述2个品种适宜红河州海拔800~1 600 m的地方推广栽培。  相似文献   

18.
为选育出矮化、早熟、早果、丰产、质优的青花椒良种,于2005年开始从九青叶花椒实生繁育群体中选出的优良单株,通过变异单株初选、复选、决选,选育出早熟九叶青花椒良种。该优良品种果实颗粒大,果型指数1.06~1.08,平均千粒重90 g^96 g;种皮麻味素含量16.4 mg·g^-1~16.6 mg·g^-1,醇溶性提取物含量18.6%~19.2%,乙醚提取物含量12.5%~12.9%,蛋白质含量14.8%~15.2%;含挥发性香味物质组分97个,其中特异香气成分物质39个。品质达到或超过国家林业行业标准规定的特级花椒。  相似文献   

19.
To clarify the behavior of whole lignins in wood cell walls during alkaline nitrobenzene oxidation, the delignification process from cell walls in normal and compression woods of Chamaecyparis obtusa Endl. (Cupressaceae) was observed using ultraviolet and transmission electron microscopies. The lignin content conspicuously decreased to around 10% after 35min in normal wood. The lignin content in compression wood finally leveled off at aroumd 10% after 50min. In gel filtration of oxidation products in ethyl acetate, a high molecular weight fraction was prominent in extracts from the early stage of the reaction. As the oxidation progressed, the high molecular weight fraction became less prominent in both normal and compression wood. Changes in the weights of cell wall residues during reaction indicated that approximately half of the components other than lignin were also removed from the cell walls. This shows that the majority of lignin with relatively high molecular weight is removed from the cell walls together with polysaccharides in the early stage of the reaction and that further oxidative degradation occurs in solution in later stages. Only a small amount of the lignin with low molecular weight could be analyzed by gas chromatography.Parts of this report were presented at the 47th (Kochi, April 1997) and 48th (Shizuoka, April 1998) Annual Meetings of the Japan Wood Research Society, and at the Lignin Symposium, Sapporo, October 1997  相似文献   

20.
Data on the seasonal patterns of fruit growth and dark respiration of two peach (Prunus persica (L.) Batsch) cultivars were combined with temperature data to calculate the carbohydrate requirements of an "average" peach fruit from bloom to harvest. The two peach cultivars used were June Lady (an early maturing (mid-June) cultivar) and O'Henry (a late maturing (early-August) cultivar). At harvest, the mean dry weight of the June Lady fruit was 17.8 g (139.7 g fresh weight) and of O'Henry fruits was 30.9 g (213.9 g fresh weight), and the times from full bloom to harvest were 107 and 154 days, respectively. The total calculated fruit respiration requirements were 132 and 300 mmol CO(2) fruit(-1) season(-1) for June Lady and O'Henry fruits, respectively. Total calculated carbohydrate requirements for fruit growth and respiration are 23.9 and 43.8 g CH(2)O fruit(-1) season(-1) for June Lady and O'Henry fruits, respectively. Fruit respiration accounted for 16.3% of the total carbohydrate requirements of June Lady fruits and 0.5% of the total carbohydrate requirements of O'Henry fruits.  相似文献   

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