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1.
马尾松切根、菌根化容器育苗效果的试验 总被引：5，自引：0，他引：5
对马尾松切根、菌根化容器育苗效果的试验表明：催芽切根的苗木的主根和高生长受到一定抑制，但地径生长、侧根发育及须根数量均有显著改善，并且避免了畸形根系的产生，从而提高了容器苗的规格质量；切根茵根化的苗木高、径生长和生物量积累均优于切根未接种菌根的苗木，幼苗造林成活串和幼林生长发育状况也明显比对照要好。 相似文献
2.
以湿加松扦插容器苗为材料,设置空气切根(30,50,70cm苗床)和不切根对照处理,分析处理后半年内株高、地径、地上部生物量、根系生物量、根长、根表面积、根直径、细根比例等指标的月变化。结果表明,控根影响了扦插苗的根系形态,但对扦插苗的生长与生物量无显著影响。处理4个月后,70cm苗床的切根处理显著促进了根系的伸长生长,但5个月时,切根苗木的根系转向粗生长的阶段,与对照相比,细根比例降低,而根直径增大。苗木生长量呈现与根直径的相关性逐渐增强、而与根长度相关性减弱的趋势,表明控根苗木根系形态的动态变化有利于促进苗木的生长。建议采用70cm苗床做湿加松扦插苗的空气切根。 相似文献
3.
菌肥对香榧等控根容器苗生长的影响 总被引：2，自引：0，他引：2
在香榧、山核桃、杨梅等控根容器苗培育过程中,选用固氮菌、解磷菌及其混合菌进行菌肥试验。结果表明:施菌肥3 a后,香榧容器苗解磷菌、混合菌处理苗高生长量比对照分别增加18.26%和18.06%,差异显著(P<0.05);山核桃容器苗固氮菌、混合菌处理高生长量比对照分别增加46.25%和47.23%,差异显著(P<0.05);杨梅容器苗混合菌处理苗高生长量与对照相比差异显著(P<0.05),明显优于它们单独使用效果;此外,不同菌肥对香榧等3种苗木地径生长也有一定的促进作用。由于不同的菌肥对各树种的苗木生长促进效果有明显差异,在苗木培育过程中,应根据不同的苗木合理选用菌肥。 相似文献
4.
红锥容器育苗的试验研究 总被引：6，自引：1，他引：5
通过开展以不同育苗基质与移苗阶段作组合和以不同断根方式与根部处理作组合的红锥容器苗育苗试验,对影响红锥容器育苗效果的因素组合进行了研究.研究结果表明:不同的处理方式对红锥容器苗的成活及生长指标存在显著的影响.其中不同育苗基质和不同断根方式是其主要的影响因素.以红泥营养杯下垫火烧土的处理对红锥容器育苗的苗木保存率和苗木高生长的影响效果最好,而以单纯红泥作为育苗基质的处理对其苗木地径生长的影响最大.以在芽苗出土前进行切根处理对于红锥容器苗的苗木保存率、苗高及地径生长影响的效果最佳.但在芽苗出土前进行切根处理则对于其苗木根系的生长更有好处. 相似文献
5.
芽苗切根移植对南酸枣苗木及造林当年生长的影响 总被引：1，自引：0，他引：1
在贵州三都进行了芽苗切根移植育苗对南酸枣1年生苗木及造林当年生长效应的研究,结果表明:1)芽苗切根移植育苗能提高苗木单株和群体质量,与常规育苗相比,芽苗切根移植育苗对苗木径生长量的提高、长5cm的侧根数量的增加及地径标准差的降低达极显著水平,对苗木高生长的提高和对高径比值、苗高标准差的降低达显著水平;2)芽苗切根移植苗造林优于常规苗造林,当年生树高、胸径生长差异达极显著水平;3)芽苗切根移植苗的高径生长节律与常规育苗一致,但各个时期的苗木高、径生长速度有差异,主要表现为缓慢生长期比常规育苗慢,快速生长期又比常规育苗快,径生长尤其突出。 相似文献
6.
《中南林业科技大学学报(自然科学版)》2017,(8)
对江南油杉轻基质容器苗的组合控根进行了研究。采用L9(33)正交试验设计方法研究了在芽苗移栽期间进行切根和外源NAA处理对容器苗内源激素含量和根系构型的影响。结果表明,切根和外源NAA共同作用对苗木生长过程中的根径、根尖数、一级侧根均长以及全株鲜质量有显著影响。通过最优组合的评定,筛选出芽苗≥2 cm且幼叶未展期进行切根,留根3 cm或切根1/2+50 mg/LNAA溶液处理为较优控根组合。组合控根有效地减少甚至杜绝了苗木盘根现象的发生。对9个处理4个测定期的内源ZR,ABA,IAA和GA3含量主体效应的检验发现,切根时期、切根方式和NAA浓度对根系内源激素含量均起到了调控作用,同时,不同的控根措施会引起不同种类内源激素含量的变化,因此,组合控根措施的筛选才成为必要。 相似文献
7.
分析山乌桕绿化大苗培育中采用控根容器和密度动态调控育苗的经营效果。采用控根容器培育的山乌桕绿化大苗与普通无纺布容器苗比,苗高间差异不显著,地径显著大于普通无纺布容器苗,高径比生长协调,苗木较粗壮,主根长显著较短,而一级侧根数和根系生物量显著大于后者。控根容器培育的苗木根系多、不缠绕、无畸形,空间分布合理,苗木质量优于后者。不同密度育苗对山乌桕2 a苗龄绿化大苗根系影响不显著,但2 a苗龄摆放密度9株/m2的苗高、地径总体表现最优。因此,山乌桕2 a苗龄绿化大苗培育进程中,采用控根容器和密度动态调控可以提高苗木质量。 相似文献
8.
为适应福建低山丘陵造林,在培育麻栎苗过程中采用了容器袋育苗、遮荫网、综合控根等措施,当年9月点播的容器苗次年2月出苗率可达到80%以上,苗木出圃规格达到合格苗标准。育苗次年在林冠下造林表现良好,当年造林成活率平均可达90%以上,保存率85%以上。在麻栎容器苗培育中,宜采用50%敌敌畏乳油1000倍液浸泡种子24 h、30~70%透光率遮阴网、使用修枝剪断根的物理切根辅以定期挪动容器苗采用空气切根进行控根处理。 相似文献
9.
《中南林业科技大学学报(自然科学版)》2016,(7)
针对江南油杉轻基质容器苗盘根较严重、侧须根少的问题,以不切根(CK)为对照,开展芽苗切根控根试验,研究留根长度和切根比例对江南油杉容器苗生长及根系构型的影响。结果表明:当茎芽高度≥2 cm时,依据胚根长比例进行切根移栽更有利于江南油杉轻基质容器苗的生长和改善根系质量,且以切根1/2效果最佳,但留根长度不宜超过4 cm。综合根系参数分析结果,与不切根相比,芽苗切根后主根长缩短26.12%~45.25%,根径增加25.33%~41.45%,一级侧根数增加15.51%~70.81%,一级侧根长度的最大增幅为50.00%~69.05%,盘根现象能减少到3.33%。本试验中,对促进生长和改善根系构型效果较好的试验处理为切根1/2和留根2 cm,由于分叉根的大量形成,侧根的萌发面积增加且形态更高级,苗木根系呈现须根化,根系构型更合理。 相似文献
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11.
红豆树根瘤的形成时间和根瘤的数量与圃地土壤的质量有关,在土壤水肥条件好的环境中,1 a生苗木中的根瘤少见,且根瘤个体极小;在土壤较贫瘠的圃地中,红豆树根瘤十分发达,数量多且形成时间早。红豆树根瘤能够促进苗木生长,有根瘤生长比无根瘤生长的1年生红豆树植株中,根系的干物质增长率46%、根系鲜重的增长率41.9%、茎干物质增长率40.3%、植株总干物质的增长率35.0%、植株总鲜重增长率22.4%、植株叶的干物质增长率14.8%。截根处理有助于根瘤菌感染苗木植株,苗木生长更健壮:截根处理的苗木径高比为4.1%,未截根处理的为3.4%;截根处理促进根系的发育,截根处理的侧根总长度47cm/株、未截根处理的侧根总长度为26cm/株、侧根增加率为80.8%,截根处理的须根总长度228cm/株、未截根处理的侧根总长度为102cm/株、须根增加比率123.5%;截根处理促进苗木根幅的扩大,比未截根处理的根幅增大27.3%。 相似文献
12.
Ozone exposure decreases belowground carbon allocation and root growth of plants; however, the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood. To evaluate the potential for plant compensation, we followed the progression of ozone effects, with particular emphasis on the development of new roots. Ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings were exposed to ozone for 2 years. Following removal of the seedlings from ozone, root growth was assessed to characterize the carry-over effects on new root production, and carbohydrate concentrations were measured to determine if allocation strategies differed among ozone treatments. Four months after removal from ozone, dormant seedlings had significantly lower starch concentrations in stems, coarse roots and fine roots than control seedlings. Following root flushing, starch concentrations in all seedlings decreased, with ozone-treated seedlings containing significantly less starch, sucrose, fructose, glucose and total monosaccharides than control seedlings. There was some evidence that stem starch was mobilized to compensate partially for the lower concentrations of root starch in ozone-treated seedlings; however, there was significantly less new root production in seedlings previously exposed to ozone for 2 years than in control seedlings. Early senescence of older needle age classes, perhaps resulting in inadequate available photosynthate, may be responsible for the reduction in new root production during the year following exposure to ozone. Stored carbohydrate reserves, which were depleted in seedlings previously exposed to ozone, were insufficient to compensate for the ozone-induced reduction in canopy photosynthate. We conclude that there are carry-over effects of ozone exposure on ponderosa pine seedlings, including an enhanced potential for seedling susceptibility to other stresses even in respite years when ozone concentrations are low. 相似文献
13.
《Forest Ecology and Management》1988,23(4):273-283
The objective of this study was to determine if seedbed substrates consisting of F and H organic matter and Ae and Bf mineral material inhibited seed germination and subsequent seedling growth of black spruce. The study was conducted with seedbed substrates collected from eight pure blackspruce stands of four age classes (15, 30, 45 and 60 years) in central Newfoundland.No significant effect on percentage germination or primary shoot growth of seedlings was obtained when grown on F and H organic matter, Ae and Bf mineral material. However, growth and development of primary roots was significantly reduced in the F and H organic matter and Ae mineral material compared to the controls (washed sand). The inhibitory effect increased with stand age. The affected seedlings did not produce normal primary roots with root hairs. The primary root cells of the affected seedlings were significantly broader and shorter compared to the control seedlings. Mineral material from the Bf horizon did not have any significant effect on primary root growth of black spruce seedlings. 相似文献
14.
应用2000,1000,500,250,125,62mLL-1TMS天目丝增抗剂对200株长白落叶松苗进行6小时浸根,在生长季节(5月30日至10月20日)对经过天目丝增抗剂处理的造林苗每隔15天测定一次苗木的高生长、地径、主根长度,侧根数。实验结果表明,天目丝增抗剂处理可以极大地促进长白山落叶松苗木生长并能提高苗木质量。500mLL-1TMS处理的苗木生长效果最好,与常规育苗相比,高生长平均增加42.5%,地径生长平均增加30.7%,主根长平均增加14.0%,侧根数平均增加31.6%;Ⅰ级苗和Ⅱ级苗各占一半,没有Ⅲ级苗,显著地提高了经济效益。表3参8。 相似文献
15.
We compared the photosynthetic and photoassimilate transport responses of Melaleuca cajuputi Powell seedlings to root hypoxia with those of Eucalyptus camaldulensis Dehnh. Control and hypoxia treated roots were maintained in a nutrient solution through which air or nitrogen was bubbled. Under root hypoxic conditions, seedlings of M. cajuputi, a flood-tolerant species, maintained height growth, whereas seedlings of E. camaldulensis, a moderately flood-tolerant species, showed markedly decreased height growth compared with control seedlings. Root hypoxia caused decreases in whole-plant biomass, photosynthetic rate and stomatal conductance in E. camaldulensis, but not in M. cajuputi. Photoassimilate transport to roots decreased significantly in E. camaldulensis seedlings 4 days after treatment and starch accumulated in mature leaves. Photoassimilate supply to hypoxic roots of E. camaldulensis seedlings was, thus, limited by reduced photoassimilate transport rather than by reduced photosynthesis. In contrast, M. cajuputi seedlings showed sustained photoassimilate transport to hypoxic roots and persistent photosynthesis, which together provided a substantial photoassimilate supply to the roots. Sucrose accumulated in hypoxic E. camaldulensis roots, but not in hypoxic M. cajuputi roots. A stable, low sucrose concentration in hypoxic roots would let M. cajuputi seedlings prolong photoassimilate transport to the roots. Photoassimilate partitioning among the water-soluble carbohydrates, starch and structural carbohydrates within the roots was unaffected by root hypoxia in E. camaldulensis, but in M. cajuputi, partitioning was shifted somewhat from structural carbohydrates to water-soluble carbohydrates. This suggests that M. cajuputi seedlings are able to increase photoassimilate utilization in metabolism and sustain energy production under root hypoxic conditions. 相似文献
16.
Root system morphology of Quercus rubra L. planting stock and 3-year field performance in Iowa 总被引：1，自引：0，他引：1
On 3 sites, 3-year performance of 1+0 northern red oak (Quercus rubra L.) seedlings was evaluated with respect to initial root system grade. Seven hundred twenty nursery-run bareroot northern red oak seedlings were graded according to numbers of large (>1mm) first-order lateral roots and outplanted in spring 1987 on eight 90-tree plots distributed among three sites in central Iowa. Survival, height growth, and diameter growth were significantly greater for seedlings with 10 or more large first-order lateral roots than for seedlings with 4 or fewer. Seedling survival and growth were significantly and positively related to initial root grade. First-year height growth, however, was significantly and negatively correlated with initial height. Combined results for seedling survival and growth indicated that red oak seedlings with five or more large first-order lateral roots have a greater probability of success both in terms of survival and early growth than do those with four or fewer first-order lateral roots.Journal paper no. J-15193 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project no. 2485. 相似文献
17.
【目的】探究不同磷水平对‘贵农5号’刺梨实生苗生长、根系形态变化的影响及其与内源激素的相互作用,了解刺梨应对低磷胁迫的适应策略,为喀斯特地区低磷土壤刺梨的磷养分管理和生长调控提供科学依据。【方法】采用基质培养方法,设5、25、45、65和85 mg·L-1有效磷含量的5个供磷水平处理,对不同处理的生长和根系形态指标及叶、根中内源激素含量进行测定,解析不同磷水平下根系形态与内源激素含量变化的关系。【结果】1) 45 mg·L-1磷水平下实生苗生长的最好,整株生物量、主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度均最大,根和叶中的GA1+3含量最高,ABA含量最低。2)供磷水平低于或高于45 mg·L-1后,植株生长受到抑制,生物量明显减小,GA1+3含量降低,ABA含量增大,上述根系形态指标变小。在5 mg·L-1的低磷胁迫下,植株根冠比、2级、3级侧根密度和根毛的密度及长度达到最大。3)根和叶中的IAA及ZR含量随磷水平的降低而增大。4)不同磷水平下植株的生长指标和生物量大小与根和叶中的IAA和ZR含量间均表现出极显著(P<0. 01)的一元二次非线性回归关系,与GA1+3和ABA的含量分别呈极显著(P<0. 01)正相关和极显著(P<0. 01)负相关。供磷水平过低、过高对植株生长的抑制是IAA、ZR、GA1+3、ABA含量改变后协同作用的结果。低磷水平下根的生长抑制与叶和根中的IAA、ZR和ABA含量增大和GA1+3含量降低有关,高浓度的GA1+3和低浓度的ABA能促进主根的伸长和侧根的形成,而高浓度的IAA和ZR对根毛的形成及伸长和增加根毛的密度有促进作用。【结论】45 mg·L-1磷水平下刺梨实生苗生长和根系发育最好,主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度最大。降低或提高磷水平后植株生长受到抑制,上述根系形态指标随之变小。低磷胁迫下刺梨实生苗根冠比和2、3级侧根密度、根毛密度及长度明显增大。供磷水平变化导致刺梨实生苗叶和根中IAA、ZR、GA1+3、ABA的含量发生改变,并共同对植株生长和根系形态变化产生协同调控作用。根冠比的增大,2、3级侧根密度和根毛密度及长度的增加是刺梨实生苗应对低磷胁迫采取的适应策略,根和叶中高水平的ZR和IAA发挥重要的促进和调控作用。 相似文献
18.
Quercus petraea was undercut according to the following procedure: undercutting first year once (July, September, November), twice (July and November), or undercutting in two consecutive years (September of year 1 and either July, September or November of year 2). Undercutting decreased height and dry weight of the seedlings compared to uncut control seedlings. Undercutting in September and July in two consecutive years increased the number of first-order lateral roots. Field performance was evaluated by transplanting under two conditions, (a) competition with a mixture of grasses with no irrigation or fertilisation and (b) standard conditions with fertilisation and irrigation first year and no competition with grass. After two growing seasons under competitive conditions, seedlings undercut in September of year 1 had a significantly higher dry weight compared with that of uncut control seedlings. Numbers of lateral roots and field performance under competitive conditions was related when numbers of lateral roots were small, but not when high. Competitive conditions had limited effect on root growth after one growing season, whereas shoot growth was reduced. After two growing seasons both shoot and root growth were reduced in all treatments compared with standard conditions. 相似文献
19.
Ten-week-old pond pine (Pinus serotina Michx.) seedlings were grown in solution culture at 5 or 100 microM P and under aerobic or hypoxic solution conditions. After 6 and 10 weeks in the treatments, changes in relative growth rate (RGR), P acquisition and allocation, and carbohydrate partitioning were determined by analyzing tissue for total P, soluble sugars and starch. Six weeks of low-P growth conditions decreased seedling dry weight and the ratio of shoot dry weight to root dry weight (S/R) by 39 and 51%, respectively, in comparison to seedlings from the aerobic, high-P (control) treatment. Mean RGRs of shoots in the low-P treatment were reduced by 33%, whereas root growth was unaffected. After 10 weeks of low-P growth conditions, however, both shoot and root RGRs were significantly reduced, and plants had lower S/R ratios than in any other treatment. Slowed shoot growth was accompanied by starch and nonstructural carbohydrate accumulation in needles, indicating that needle growth was not limited by carbohydrate supply. Six weeks of low-P growth conditions decreased total seedling P by 75%, reflecting a 97% reduction in the net uptake rate (NUR). Shoot NUR as a fraction of seedling NUR was also greatly reduced in the low-P treatment, indicating that low-P growth conditions affected P translocation to the shoot more than P accumulation by roots. In contrast, 6 weeks of hypoxic growth conditions decreased total dry weight of seedlings in the high-P treatment by 41% relative to their aerobic counterparts. Root growth was affected more than shoot growth, however, and S/R ratios increased. After 10 weeks, S/R ratios doubled, primarily because of the reduction in root RGR. Nevertheless, roots of hypoxic seedlings contained a higher percentage of total seedling P than their aerobic counterparts. Net P acquisition per seedling decreased by more than 50% under hypoxic growth conditions, as a result of reductions in both root RGR and seedling NUR. Starch accumulation in shoots of hypoxic seedlings reflected reductions both in root growth and in transport of carbohydrates to nonwoody roots. Carbohydrate availability did not appear to be limiting growth of hypoxic woody roots, which are well-aerated internally, but it may have limited metabolic processes in nonwoody roots of seedlings from the high-P treatment. 相似文献