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核桃是我国重要的经济树种。过去,人们多采用实生繁殖技术发展核桃生产。采用这一技术,有许多弊端:核桃树的后代分离变异较大,结果晚,产量低,质量差。只有通过嫁接繁殖,核桃树才能很好地保持母本的优良性状,提高产量和品质,提早结果,实现良种化生产和集约化经营,更好、更快地取得经济效益。 相似文献
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核桃栽培,在我国已有两千多年的历史。自古以来,除少数地区外,都是采用实生繁殖。它虽然是雌雄同株,但大部分花期不遇(表1)。据观察,同一植株的雌雄花期,有前后相隔两周的,因而,核桃大部分植株均系异花授粉。实生繁殖的后代分离,单株差异很大,类型复杂,不能保持母树的优良特性,造成了核桃产量低、品质劣、进入结果期晚的现状。针对实生栽培存在的问题,我们就应该像栽培苹果那样,走无性繁殖的道路。苹果的今天,就应该是核桃的明天;苹果所走的道路,就是核桃应该走的道路。否则,想提 相似文献
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核桃是重要的木本油料和优良的干果。近几年来,由于生产的发展,品种问题已经提上了议事日程,良种已逐步为人们所重视、所认识。各地都不同程度地开展了选种工作,初步选出了一批品种(类型)或单株。我省各核桃主产县,也陆续进行了株选,初步选出第一批20个优良单株。核桃是雌雄异花同株,风媒花,由于天然杂交的结果,种子繁殖的后代发生着广泛的实生变异。过去的所谓核桃“品种”,实际上是一个遗传性极其多样而部分性状较接近的复杂群体.用这些“品种”的天然杂交种子繁殖的后代必然更为多样,这就是核桃 相似文献
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普通油茶实生繁殖性状遗传变异的研究 总被引:1,自引:0,他引:1
《西部林业科学》1976,(2)
油茶,是一种重要的木本油料树种。在生产中,多采用种子繁殖,有的地方较为重视选种工作,选择油茶优良单株作采种母树。但是,其实生繁殖后代是否能保持母本的优良特性,是一个值得研究的问题。为了摸索油茶实生繁殖性状遗传变异的规律,我们遵照毛主席“真理的标准只能是社会的实践”的教导。我站从1971年起开展了对油茶实生繁殖性状的研究工作。现将工作进展情况,小结如下:自然概况与工作方法广南位于我省东南部,东经105°21′, 相似文献
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核桃是我国重要的木本油料树种,因实生苗木变异大,生产上多采用实生苗嫁接的方法来保持其优良性状,应用最多的为方块芽接. 相似文献
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漾濞泡核桃是全国有名的优良品种,历来被各地引种。但由于长期进行嫁接繁殖对其实生后代的变异情况不清楚。产区群众有泡核桃不嫁接会变成夹绵核桃,夹绵核桃不嫁接会变成铁核桃之说,但无实生植株作证。国内外的核桃育种研究和我省核桃实生 相似文献
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黄森 《内蒙古林业调查设计》2011,34(2):27-28
东北红豆杉,又名紫杉,是第三纪孑遗的珍贵树种。红豆杉资源的保存和种苗的快速繁育,是解决紫杉醇用材林的基础,大面积营造红豆杉人工林是解决紫杉醇原料的关键。用红豆杉种子繁殖苗木时,要注意种子的储存方式,要沙种混藏或控温处理,这对越冬后出芽和打破休眠习性,具有很好的效果。播种前要搓伤种皮、温水浸种、药剂素处理。 相似文献
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Larchisoneofthemainspeciesforfast-growingandhigh-yieldplantationsinNortheastChina,especialIyLarixolgensisHerry-ItsmeanannualincrementcanevenreachlO.l-lO.6m3/hm2intheear1y3OyearsinrelativecoldYichunRegion.P1ant-ingfast-growingandhigh-yieldplanta-honsrequirehighqua1itysite.Buttherearetoolittlehighqualitysitetosatisfythede-mandoffast-growingandhigh-yieldplantationsinforestregionsofNortheastChina.MostoftheplantationshavetobeplantedonstublandofformerLarchplan-tations,Thus,#theeffectsofsecondr… 相似文献
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Seeds of Celtis australis were collected from 13 different sources, ranging from 550 to 1980 masl, in Central Himalaya, India. Significant (p = 0.05) variations were observed for seed traits among provenances. However, among various characters, seed weight exhibited
maximum variation between seed populations compared to other morphological characters. Between provenances, seed weight ranged
from 47.8 to 83.1 g/1000 seed, with mean value of 66.9 ± 10.7 g/1000 seed. Significant (p = 0.01) positive correlation was found between morphological characters of seeds including seed weight and elevational range
of seed source. For one year old seedlings, average shoot and root growth was 61.1 ± 13.3 and 30.5 ± 5.4 cm, respectively,
irrespective of provenance variation. Inter-comparing biomass yield of the seedlings with altitude, average biomass production
was 8.4 ± 2.5, 9.4 ± 3.3 and 12.7 ± 1.7 g/plant, respectively, for low (550–1000 masl), middle (1050–1250 masl) and high (1350–1980 masl)
altitudinal populations. Significant (p = 0.01) positive correlation between growth performance of seedlings and altitude of the seed source was recorded. Across
the provenances, shoots had the highest proportion of total biomass (42.3%), followed by leaves (32.6%) and roots (24.6%).
Among various provenances, Badiyargaon, Agroda, Guptakashi, Jakholi, Gajeli, Srinagar and Palampur populations produced heavier
seedlings and grew faster compared to seedlings of other sources. 相似文献
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采用种衣剂拌种进行沙棘育苗试验,当年秋季进行沙棘苗生长量和苗木产量的调查,探讨种衣剂拌种对沙棘种子繁苗效果的影响。结果表明:包衣剂拌种能够显著提高沙棘苗木生长量,比对照多繁育27万株·hn-2;种衣剂拌种后繁育的苗木苗高、地径与对照差异显著,苗高比对照提高48.65%,地径提高33.34%;主根长较对照提高43.7%,差异达极显著水平;侧根数提高18.8%,差异不显著;种衣剂拌种后沙棘苗木根系腐烂率为8.9%,比对照低4.3个百分点。种衣剂拌种是半干旱区繁育沙棘优质苗木的有效技术措施。 相似文献
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Stem cuttings of Eucalyptus globulus are used within tree improvement programs and for mass deployment. To be successful, cuttings must perform as well or better than seedlings. The root systems of cuttings are fundamentally different from those of seedlings. If these differences influence growth, the differences and their consequences must be identified and the propagation system manipulated to improve performance of the propagules.Cuttings are only a viable alternative to seedlings as planting stock if the method of propagation does not affect their growth and development adversely. Full-sibling cuttings and seedlings of Eucalyptus globulus were compared under controlled environmental conditions to minimise extraneous sources of variation, and to establish whether changes in growth or development were induced by propagation. On three occasions over a period of eight weeks root-collar diameter, shoot height, leaf and stem weight, shoot/root ratios and root system morphology were measured on cuttings and seedlings. Seedlings were taller than cuttings throughout the experiment, but both plant types had similar height growth rates. Diameter growth rates were lower in cuttings than seedlings, and there were differences in both height and diameter growth rates between families. Root system configuration differed between the plant types. Seedlings had strongly gravitropic tap-roots, with two types of primary roots from which secondary roots emerged. Cuttings had no tap roots, and the main structural components of their root systems were adventitious roots formed during propagation. Cuttings did not develop further structural roots during the experiment, whereas seedlings continued to develop primary roots. Individual primary roots of cuttings were longer and had larger mid-point diameters than those of seedlings, but the total length of primary roots was greater in seedlings. Seedlings also had a greater number and total length of secondary roots. Shoot/root ratios, calculated from a range of functional measures, were higher in cuttings than seedlings. 相似文献
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Catherine Ky-Dembele Mulualem Tigabu Jules Bayala Per Christer Odén 《Agroforestry Systems》2014,88(2):311-320
Within- and between-provenance variations in seed and seedling traits of Khaya senegalensis A. Juss were studied at INERA in Burkina Faso. Nursery grown seedlings from four provenances in Burkina Faso were used for the study. The studies revealed significant variability in all traits evaluated. Seed length and weight significantly varied among provenances and families within provenances, where Bopiel and Koyenga had the highest mean values. Height and root collar diameter of 1 year old seedlings significantly varied among families within provenances. Except leaf biomass ratio and carbon isotope ratio which varied significantly among provenances but not among families within provenances, all other seedling biomass traits—total plant biomass, stem biomass ratio, leaf biomass ratio, root biomass ratio, root shoot ratio, specific leaf area, and leaf area ratio were significantly affected by provenances and families within provenances. The magnitude of variation due to family effect ranged from 65 to 93 % for seed size traits, and from 4.5 to 17.8 % for seedling characters. Estimates of family heritability were moderate to high (0.67–0.95) for seed traits, but low to moderate (0.19–0.59) for seedling characters, indicating that much of the total variation in seed traits is due to the genetic effect. The two most prominent provenances, Koyenga and Bopiel, with higher seed size and greater seedling growth could be considered for an eventual K. senegalensis improvement program in Burkina Faso. 相似文献