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161.
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163.
ZHENG YongqiResearch Institute of Forestry. Chinese Academy of Forestry. Beijing 《中国林业科技(英文版)》2002,(1)
Family outcrossing rates of Pinus caribaea var. caribaea populations that differed in origin and management were estimated by using isozyme markers. The family outcrossing rates were estimated by (1)fixing the probability of pollen gene frequency (p); (2) allowing pollen gene frequency to vary among families. The estimates of family outcrossing rates for all the populations varied widely among families (clones of the seed orchard), ranging from 0.39 to 2.0. The average family outcrossing rates of both methods were greater than the 相似文献
164.
Eiji Hayashi Kazuya Iizuka Shin-ichi Sukeno Kohzo Kohno 《Journal of Forest Research》1998,3(2):119-122
We determined the survival rate of tree families produced by the intra- and interspecific crossing of larch species damaged
by browsing of vole (Clethrionomys rufocanus bedfordiae Thomas) and the contents of ether extracts (EE) in their bark. The average survival ofLarix gmelini var.japonica Pilg. (L. gmelini)×L. gmelini (G×G) was highest, followed by the hybridL. gmelini×L. leptolepis Gordon (G×L). The families of the hybrid G×L, which is considered suitable for silviculture in Hokkaido, Japan, showed significant
differences in survival rates, suggesting that it is possible to produce improved varieties of the hybrid which are more resistant
to vole browsing. The EE contents of the bark were under strong hereditary control, and the rank of the EE content among the
various families hardly fluctuated between the location of the test fields. The correlation coefficient between the survival
rates and the EE contents was highly significant (r=0.89,n=24,p<0.01), indicating that the EE content in the bark may be used as a possible index of resistance or susceptibility to vole
browsing in larch plantations.
A part of this report was presented at the 106th Annual Meeting of the Japanese Forestry Society, at Sapporo, April, 1995. 相似文献
165.
优良木(Ⅰ、Ⅱ、Ⅲ级木)的成长和分化,被压木(Ⅳ、Ⅴ级木)的衰退和死亡,是思茅松林分演变过程中相互联系的两方面。林分平均直径的变化与“内部时间(T=D)”有关系。由“内部时间(T=D)”刻划的“立木度/蓄积度”序列,与由“内部时间(T=D)”刻划的“株数递减率/蓄积量递增率”序列的相互关联关系,反映出林分结构状态的演变。在8、16、32这几个临界时刻,“立木度/蓄积度”的数值都趋近10,这是思茅松林分演变的3个周期,对应着周期性的转移概率序列。用在判断林分生长、预测林分演变过程、确定林分间伐强度等方面都有使用价值。 相似文献
166.
Distribution of ectomycorrhizas and ectomycorrhizal fungal inoculum with soil depth in a birch forest 总被引:2,自引:0,他引:2
The distributions of ectomycorrhizas and ectomycorrhizal fungal inoculum with soil depth (0–45 cm) were determined in a 40-year-oldBetula platyphylla var.japonica forest. Mycorrhizal and non-mycorrhizal fine roots were measured in each soil core sample that was collected at soil depths
of 0–5, 5–10, 10–15, 15–20, 20–25, 30–35, and 40–45 cm. The ectomycorrhizas were mainly distributed (>50%) in the top soil
(0–5 cm) of organic forest floor horizons. Below 5 cm the quantity of ectomycorrhizas decreased sharply. The percentage of
fine roots which were ectomycorrhizal gradually declined with the depth of soil. The ectomycorrhizal fungal inoculum was evaluated
by a bioassay method, measuring the lengths of the entire root system and of the ectomycorrhizal roots of birch seedlings
planted in each soil sample. The soil samples were collected from 0–5, 10–15, 20–25, 30–35, and 40–45 cm depths of the soil
profile. Ectomycorrhizal formation on birch seedling roots in the bioassay was high in both the soil depth intervals 0–5 cm
and 10–15 cm, while the amount was lower in the soil depth interval from 20–45 cm. The results of these investigations show
that the amount of the ectomycorrhizas in soil, and the ectomycorrhizal fungal inoculum potential as determined by bioassay,
are not always consistent with each other. 相似文献
167.
红豆杉及南方红豆杉体细胞胚胎发生的研究 总被引:20,自引:0,他引:20
利用江西的红豆杉(Taxuschinensis)、福建的南方红豆杉(Taxuschinensisvar.mairei)以及四川的南方红豆杉(Taxuschinensisvarmairei)的成熟胚为试验材料,成功地诱导出大量的愈伤组织。这3种材料愈伤组织的最高诱导频率分别为957%、984%、917%。细胞学和形态学的观察结果表明:在适当的条件下经过一段时间的培养,这些愈伤组织能够产生处在不同发育阶段的体细胞胚。上述3种植物材料每100块愈伤组织平均最多分别可产生127、91和33个体细胞胚。 相似文献
168.
杏属植物为蔷薇科李亚科杏属木本植物,本文研究的西伯利亚杏(Armeniaca sibirica (L.) Lam.)、东北杏(Armeniaca mandshurica (Maxim.) Skv.)和普通杏的野生类型-野杏(Armeniaca vulgaris Lam. Var.ansu (Maxim.) Yü et Lu),通常为落叶乔木或灌木,原产于大陆性干燥山区,多分布于半干旱、半湿润的风沙平原、山地和丘陵地区[1],喜光、抗寒、耐旱、耐瘠薄、耐风沙、根系发达、萌蘖能力强、容易繁殖、生长快、病虫害少,是固沙保土、涵养水源、改善生态环境的优良乡土树种,并且有较高的经济价值及药用价值[2-6],其中杏仁油可以作为功能性食品保健植物油、高级润滑油、高级化妆品和高级涂料的优质原料[7],也是值得推广种植的木本生物柴油物种[8],杏仁蛋白是一种食用价值极高的植物蛋白[9],杏壳作为优质活性炭的原料也是其重要的副产品[10]. 相似文献
169.
采用沙黄松天然林自由授粉家系7年生树干材积的材料,分析了联合选择遗传增益结构模式。结果表明:亚群体间存在极显著差异,亚群体内家系间差异不显著;联合选择增益结构模式为亚群体间72.44%、亚群体内家系间3.55%、单株间24.01%。 相似文献
170.
ThediseasedyellowneedlesofPinusrylvestrisvar.mongoliaLitvinwerecollec-tCdinAershanForestBureau,theNeiMonggolAutonomousRegionandintheforestareasofHeilongiiangProvince.Theseneedleswereculturedundercertainrelativehumidityandtemperatureinroom,andconidiaandcirrhiwereproduced.ThefungiwasidentifiedasDeuteromycotina,Coelomycetes,Sphaeropsidales,Hender-sonia.Basedonthereport(Wehmeyer,l946),therearetwospeciesofHendersorniaonpinesandaccompaniedbyLoPhodermelIa.Thesetwofungicansup-presstheapotheci… 相似文献