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杂种二代落叶松增产能力的研究 总被引：1，自引：0，他引：1
为研究落叶松杂种二代的增产能力，１９８６年和１９８８年分别在杂种落叶松种子园内分家系采７个杂交组合的种子育苗，并进行造林试验。结果表明，杂种二代具显著增产能力，遗传力较高，家系内变异系数大，适应性强，遗传基因丰富。 相似文献
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《技术与市场》2001,(2)
波尔山羊杂交改良技术１．级进杂交以优良品种波尔羊公羊，连续同被改良品种（如本地山羊）母羊及各代杂种母羊交配，一代一代配下去，使其后代能接近或达到改良品种的生产性能和其他特性。例如，用波尔羊公羊与本地山羊的母羊进行交配，所生下来的后代称杂交一代。杂交一代中的公羔肥育后上市，母羔经选择后留神，继续与波尔羊公羊进行交配，所生下来的后代中母羔继续留种，再与波尔羊公羊进行交配，这就是级进杂交。通过级进杂交，使得后代中波尔羊的血缘成份越来越多，生产性能也越来越接近于波尔羊，这是提高本地山羊的有效办法。级进杂交另一个好处是。这样培育出来的羊更能适应本地的条件。本地山羊用波尔羊连续杂交后的二代、三代，在外形、毛色等方面，已基本接近波尔山羊。级进杂交是进行大规模改良的有效办法，采用得当，效果就好，速度就快，它是改良我国山羊品种的主要方法。如果在某一个地区能系统、连续地使用波尔羊进行与本地羊的杂交改良，则该地区应完全有可能培育出适应本地条件的新品种。２．经济杂交经济杂交是利用两个品种间杂交产生的一代杂种供商品生产之用的一种生产手段。它是利用不同品种进行杂交，以获得具有生活力强、生产发育快、饲料报酬高、产品质量好等优势的杂种一代。... 相似文献
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<正> 我所于1963年克服了小叶杨、胡杨间远缘杂交的困难,获得了小叶杨×胡杨的胡杨类型和小叶杨类型的二种F_1杂种,并于1978—1979年利用15年生的小×胡F_1(小叶杨类型)进行了回交、自交及和其它速生杨树的较为广泛的杂交,产生了大量的第二代杂种。按表型观察不仅小×胡F_1的胡杨类是真正杂种,并且经回交证明,小叶杨类型也是真正杂种。小叶杨类型还是一种具有能育,易于繁殖和易于和其他杨树杂交的育种学重要特性的杂种。幼苗盐土锻炼及盐培鉴定证明若干杂种二代较现有杂种杨如小×钻等具有了更大的耐盐性。因而在具有胡杨遗传因素的速生原始材料中,为 相似文献
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本文以桉树新造林、一代萌芽更新林、二代萌芽更新林根际土壤微生物为研究对象,采用Biolog方法测定了萌芽更新对桉树根际土壤微生物群落功能多样性的影响。结果表明：随着培养时间的延长,各样点土壤微生物利用碳源的能力呈上升趋势,土壤微生物碳源平均颜色变化率排序为一代萌芽林〉二代萌芽林〉新造林;一代、二代萌芽林和新造林根际土壤中微生物群落具有明显的分异,起分异作用的主要碳源分别为羧酸类物质、多聚物类和氨基酸类;不同萌芽代数根际土壤中被利用碳源的丰富度和多样性指数之间的差异不显著。 相似文献
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天麻种子发育成天麻球茎，翻挖出来的米麻和白麻称一代种。一代种经扩大栽培后翻挖出来的种麻称二代种，二代种翻挖时已有箭麻形成。通过一、二代种麻的翻种，找出有优势，产量高的杂交组合种进行繁殖。杂交二代种形成的箭麻，既可作商品麻，又是进行杂交育种的种麻。另有不断的杂交繁殖才能筛选出高产优质的栽培品种。第三代天麻翻挖、所收天麻中的米麻、白麻与箭麻约各占一半。白麻和米麻作最后一次栽培。否则将因麻种退化、造成“越种越小，越种越少”的现象。 相似文献
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对青山林场14年生落叶松杂种F2代2组子代测定林进行分析,探讨杂种落叶松F2代是否存在较大的分离,杂种后期生长优势能否保持.试材包括日本落叶松×兴安落叶松、日本落叶松×长白落叶松、兴安落叶松×日本落叶松.研究结果表明,杂种F2代的树高同F1代相比未存在较大分离,变异系数平均只增加了2.3%和5.8%,杂种优势稳定且具有较大生产潜力,营建杂种F1代种子园是我国高寒地区大量生产具有较高遗传增益杂种种子的途径之一.7个杂种F2代家系树高、胸径和材积家系内存在一定幅度的变异,变异系数随着树木年龄的增加而减小,14年、8年、7年和6年生树高的变异系数分别为17.6%、22.1%、23.9%和24.3%.15个杂种F2代家系随着树木年龄的增长,增产幅度呈下降趋势,但仍具有较大的杂种优势.以小北湖种源作参照,14年生高生长比8年生下降了18.5%,相比于长白落叶松种子园则下降了10.3%,杂种优势下降了2.4%,但14年生杂种F2代生长优势仍然明显,树高、胸径和材积分别超过优良种源小北湖28.1%、43.8%和123.8%,超过长白落叶松种子园7.8%、15.7%和33.8%,杂种优势为7.1%、4.1%和12.1%.7个杂种F2代家系树高、胸径、材积遗传力较高,属于强度遗传,遗传增益都在10%以上,材积的遗传增益高达33%,所以杂种落叶松F2代仍可以利用. 相似文献
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Larch is one of the most important plantation species in the northeast region of China. After clear cutting of larch plantations it is the urgent problem to besolved that whether the second generation is continuously plant6d, whether the soil fertility is decreasing and the plantstion is how to be managed onthe forestry produCtion. In odder tO realize the secondgenerahon Of larch plantstions and to provide thetheoretical base and the reasonable managementmeasures, we inventoried the groWth o… 相似文献
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The efficacy of stump treatment with 40% urea solution and spore suspension of Phlebiopsis gigantea against primary infection by Heterobasidion spp. on hybrid larch (Larix × eurolepis) was tested in two field studies in southern Sweden. In the first study, stumps treated with urea or P. gigantea were sampled by cutting a cross‐section disc after 3 months following exposure to natural conditions, and in the second study, stumps treated with only P. gigantea were sampled after 2 months. Spore traps made from hybrid larch, Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) were used to estimate the abundance of ambient spores of Heterobasidion spp. in the second study. Urea significantly reduced infection frequency of Heterobasidion spp. compared to the control. Phlebiopsis gigantea was less effective at reducing infection frequency in the first study than in the second study. Infections were caused by both H. parviporum and H. annosum sensu stricto. The amount of H. annosum infection in proportion to Heterobasidion spp. was significantly lower on the stumps treated with P. gigantea compared to the control; however, the proportion of H. parviporum on the treated stumps was not higher than the control in the first study. Spore traps made of Scots pine had a significantly higher frequency of infection than Norway spruce and hybrid larch. Only the spore traps made of hybrid larch showed significant correlation with the control stumps in terms of relative infected area. Conclusively, it seems prudent to protect hybrid larch stumps from primary infection by Heterobasidion spp., and both urea and P. gigantea can be recommended as stump treatment agents on hybrid larch, even if urea seemed to present more stable results. 相似文献
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经过20多年观测得知,以日本落叶松为亲本分别与长白落叶松、兴安落叶松、欧洲落叶松、华北落叶松杂交都有杂种生长优势,且苗期、早期（10年生幼树）优势表现明显;杂种生长优势是变动的,随着林龄增长杂种优势逐渐缓慢递减;部分杂种组合在16～21年生时,其生长低于母本日本落叶松,但仍然高于父本长白、兴安、欧洲、华北落叶松。杂种优势的高低、延续时间的长短与亲本选用、组合搭配、杂种生长节律及立地环境都有关系,且一般母本作用大;准确选用亲本,杂交效果会更好;利用杂种生长优势的最好形式是建立杂交种子园,杂交种子园杂种出现率的高低取决于两个亲本雌雄花期的同步程度;选择无亲缘关系的杂种第一代优树通过嫁接建立杂种落叶松种子园是生产大量优良杂种的好形式。 相似文献
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The hybrid larch F(1) (Larix gmelinii var. japonica × Larix kaempferi) is considered one of the most important tree species not only for timber production but also as an afforestation material for severe conditions such as infertile soil. To predict the ability of hybrid larch F(1) as an afforestation material under potential climates in the future, it is important to understand the response of hybrid larch F(1) to elevated CO(2) concentration ([CO(2)]) under low nutrient availability. Three-year-old seedlings of hybrid larch F(1) were grown under two different levels of [CO(2)], 360 (ambient) and 720 μmol mol(-1) (elevated), in combination with two different levels of nitrogen (N) supply (0 and 30 kg ha(-1)) for one growing season. Elevated [CO(2)] reduced the maximum rates of carboxylation and electron transport in the needles. Net photosynthetic rates at growth [CO(2)] (i.e., 360 and 720 μmol mol(-1) for ambient and elevated treatment, respectively) did not differ between the two CO(2) treatments. Reductions in N content and N use efficiency to perform photosynthetic functions owing to the deficiency of nutrients other than N, such as P and K, and/or increase in cell wall mass were considered factors of photosynthetic down-regulation under elevated [CO(2)], whereas stomatal closure little affected the photosynthetic down-regulation. Although we observed strong down-regulation of photosynthesis, the dry matter increase of hybrid larch F(1) seedlings was enhanced under elevated [CO(2)]. This is mainly attributable to the increase in the amount of needles on increasing the number of sylleptic branches. These results suggest that elevated CO(2) may increase the growth of hybrid larch F(1) even under low nutrient availability, and that this increase may be regulated by changes in both crown architecture and needle photosynthesis, which is mainly affected not by stomatal limitation but by biochemical limitation. 相似文献
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A method was developed for estimating the frequency of hybridsin the seed crop of a multiclonal hybrid larch seed orchardusing isozyme genetic markers. The technique was used to monitorthe output of a commercial hybrid larch seed orchard. Amongthe seeds collected from European larch clones, some 65 percent were hybrid, compared with 19 per cent from Japanese larchclones. Unequal reproductive effort and differences in floweringtime between the two parental species may account for the results.Possible application of these techniques for the certificationof seed and planting stock are discussed. 相似文献
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The flow of labeled carbon in ectomycorrhizal and non-ectomycorrhizal seedlings of Japanese larch (Larix kaempferi Sarg.) and its F1 hybrid (Larix gmelinii Rupr. x L. kaempferi) was studied. Larch seedlings were grown in a greenhouse for 110 days with larch forest soil (FM) or Suillus grevillei (SM) inoculum, or in the absence of ectomycorrhizal fungi (NM). Shoots of colonized and NM seedlings were exposed to a pulse of 14CO2 for 1 h under natural light. Seedlings were harvested following 0, 6 and 24 h of exposure to 14CO2. At the final harvest, SM seedlings of Japanese larch and hybrid larch allocated 2.6 and 2.5% more 14C, respectively, to roots than NM seedlings. In contrast, FM seedlings of Japanese larch and hybrid larch allocated 6.5 and 18.0% more 14C, respectively, to the stem than NM seedlings. Of the total 14C detected in needle, stem and root fractions, FM and SM seedlings allocated a greater proportion than NM seedlings, perhaps because FM and SM seedlings had significantly (P < 0.05) higher photosynthetic rates than NM seedlings. As a result, FM and SM seedlings had greater dry masses than NM seedlings. Concentrations of nitrogen and phosphorus in FM and SM seedlings were significantly (P < 0.05) higher than in NM seedlings, as was stomatal conductance. 相似文献
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Mika Takiya Hiromasa Koyama Kiyoshi Umeki Michiyasu Yasaka Yasuyuki Ohno Ichiro Watanabe Kazuhiko Terazawa 《Journal of Forest Research》2010,15(3):149-160
We examined the effect of early and intense pruning on light intensity under the canopy, individual growth, diameter–height
relationships, and epicormic shoot dynamics in young hybrid larch (Larix gmelinii var. japonica × L. kaempferi) to establish a new effective management method for hybrid larch plantations. The objective is to produce high-quality wood
while reducing silviculture costs using a combination of low-density planting and early and intense pruning. In a young hybrid
larch plantation, we pruned branches to two different heights (2 and 4 m above ground level) using a no-pruning treatment
as a control. Although the growth rates were lower in the heavy pruning treatment (4 m above the ground level) than in other
treatments in the year following pruning, when measured 4 years later, growth did not differ between treatments. The number
of epicormic shoots increased in the year following pruning, as did the relative photosynthetic photon flux density (rPPFD).
The number of epicormic shoots was also dependent on the size of individual trees. However, survival of epicormic shoots was
not sufficiently high to be problematic for high-quality timber production. If branches are pruned carefully such that the
rPPFD does not rise above 20%, the emergence of epicormic shoots can also be controlled. Our results indicate that early and
intense pruning is an effective component of a new management system for hybrid larch plantations. 相似文献
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英国西加云杉和落叶松的无性繁殖 总被引：2，自引：2，他引：2
本文概述了英国西加云杉和落叶松无性繁殖的历史、研究背景、生产方法、扦插苗的造林表现和大规模应用的发展前景。目前已优化无性繁殖系统的扦插苗生产成本为常规的１／３，且扦插苗不增加造林成本。 相似文献
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We evaluated the response of Japanese larch (Larix kaempferi Sieb. & Zucc.) to elevated atmospheric CO(2) concentration ([CO(2)]) (689 +/- 75 ppm in 2002 and 697 +/- 90 ppm in 2003) over 2 years in a field experiment with open-top chambers. Root activity was assessed as nitrogen, phosphorus and potassium uptake rates estimated from successive measurements of absorbed amounts. Dry matter production of whole plants was unaffected by elevated [CO(2)] in the first year of treatment, but increased significantly in response to elevated [CO(2)] in the second year. In contrast, elevated [CO(2)] increased the root to shoot ratio and fine root dry mass in the first year, but not in the second year. Elevated [CO(2)] had no effect on tissue N, P and K concentrations. Uptake rates of N, P and K correlated with whole-plant relative growth rates, but were unaffected by growth [CO(2)], as was ectomycorrhizal colonization, a factor assumed to be important for nutrient uptake in trees. We conclude that improved growth of Larix kaempferi in response to elevated [CO(2)] is accompanied by increased root biomass, but not by increased root activity. 相似文献
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Yan Shanchun Fang SanyangNortheast Forestry UniversityLiu YouqiaoInstitute of Zoology Academia Sinia BeijingLiu KuanyuNortheast Forestry UniversityWang ChaomengForest Protective Station of Wurjihan China 《林业研究》1993,(2)
The tortricid moths damdging Dahurian Larch(larix gmelini Rupr.)cone weresurveyed in a matural larch forest in Wurjihan in the eastern parrt of Inner Mongolia,China from 1988 to 1989,and the population dynamics of the moth is investigated inKuduer.Jiwen and other neighbor areas.The tortricid moth was identified to be Cydiaillutana dahuricolana(V.I.Kuznetzov),the first recored in China.It has one generation ayear,and overwinters in pupae in the eastern part of Inner Mongolia.The characteristics ofthe larvae and pupae are descrbed in detail,its life habit and damaging are preliminarilystudied.The differences of its occurence in different areas are disscussed by combining withmeteorological factors. 相似文献