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1.
Recently, breeding programs have attempted to produce high growth rates for shorter rotation cycles in plantation trees. In these trees, the ratio of juvenile wood increases; thus, the juvenile wood properties should be improved for structural use. To this end, it is important to understand the influences on juvenile wood properties precisely. In this study, we report on the indole acetic acid (IAA) amounts of juvenile sugi (Cryptomeria japonica) trees in September and compare the IAA amounts to those in mature trees. The IAA amounts at the lower trunks in juvenile trees were significantly larger than those in mature trees and the IAA amounts decreased with tree height. In each stand, except a mature tree stand, there is no significant effect of IAA amounts on latewood width and MFA. However, put together all samples, the latewood width and MFA increased with IAA amounts in samples with IAA <200 ng/cm2. The samples at lower trunk in juvenile trees had significantly larger IAA amounts, larger MFA and larger latewood width than the samples in mature trees (p < 0.01). The very large IAA amounts may have a certain relation with juvenile wood properties.  相似文献   

2.
Indole acetic acid (IAA) was believed to be an important regulator in xylem formation in conifers. However, few studies have been done on the endogenous amount of IAA in cambial region tissues in sugi (Cryptomeria japonica) trees. In this study, we report the IAA amounts in the lower and upper trunk of mature sugi cultivars (Kumotoshi, Yaichi and Obiaka) in September, and the effects of growth traits on the IAA amounts. The effect of height position (lower or upper trunk) on IAA amounts was found to be larger than that of genetic variation (Kumotoshi, Yaichi or Obiaka) by two-way ANOVA. There was no significant interaction effect (genetic variation × height position). The IAA amounts of all trees varied from 3 to 42 ng/cm2 at the lower trunk and 9 to 47 ng/cm2 at the upper trunk. Crown length and distance from crown base had significant positive and negative effects on IAA amounts in the trunk of sugi cultivars, respectively. Distance from crown base had a larger effect on IAA amounts than crown length. In Yaichi, taller trees had larger IAA amounts at both the lower and upper trunk.  相似文献   

3.
Changes in plant hormones and metabolites in long-shoot stems of interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) during cone induction by gibberellic acid (GA) treatment were analyzed by high performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. A mixture of GA(4) and GA(7), including small amounts of GA(3) and GA(1), was stem-injected into each tree in amounts of 0, 4, 40 or 400 mg. One week after injection, concentrations of GA(4), GA(7) and GA(3) were elevated in all GA-treated samples. The ratio of GA(4) to GA(7) decreased significantly at Week 3. Absolute concentrations of all gibberellins declined sharply at Week 3 after GA application. After 5 weeks, GA(1) and GA(4) were below detection limits in all samples, and GA(7) and GA(3) were found only in the samples from trees treated with 40 or 400 mg of GA. Endogenous indole-3-acetic acid (IAA) concentrations increased following GA injection, and peaked at Week 2 or Week 3 in the trees treated with 40 or 400 mg GA, respectively. Injection of 400 mg of GA brought about a twofold increase in IAA concentration compared with control values. Injection of 40 and 400 mg of GA caused significant increases in stem dry mass in Week 5. Seed orchard data revealed that injection of either 40 or 400 mg GA enhanced female cone formation, whereas male cone formation was enhanced only by 400 mg GA. Slight decreases in concentrations of abscisic acid (ABA) and isopentenyl adenosine were observed after GA application. No significant changes were detected in the concentrations of ABA metabolites except for a slight decrease in the concentration of 7'-hydroxy ABA. The concentration of ABA declined during the growing season and the concentration of ABA glucose ester increased correspondingly.  相似文献   

4.
Indole-3-acetic acid (IAA), carbohydrates, total nitrogen and amino acids in the cambial region and bark were measured at the top (10-year-old internode) and bottom (1.3 m) of the main stem of 50-year-old Pinus sylvestris L. trees, having different rates and longitudinal gradients of annual ring width formation. The trees were sampled during the most active period of wood production (June 23, July 15) and at the end of this period (August 23). Trees with a small crown and relatively slow growth rate (S-trees) were compared with trees in the same stand that had a large crown and fast growth rate (F-trees) as a result of thinning and fertilization. The effect of bottom pruning fast-growing trees (pruned F-trees) was also investigated. The F-trees had greater wood production than the S-trees at both the stem top and bottom. The difference was larger at the stem bottom, thus the relative decrease in ring width down the stem was steeper in the S-trees. The amount of sucrose and IAA per cm(2) in cambial region tissues was higher in F-trees than in S-trees. However, the differences in annual ring width between treatments and within trees were not reflected in the concentrations (expressed per gram fresh weight) of these substances, measured either in differentiating xylem, the cambium plus phloem, or in the cambial region as a whole. The concentrations of total nitrogen and amino acids were slightly higher in the F-trees than in the S-trees. Pruning the F-trees reduced wood production, particularly at the stem bottom, inhibited the springtime increase in starch, and decreased the amounts of sucrose and IAA per cm(2) in the cambial region. However, it was evident that the concentrations of sucrose, IAA, amino acid and nitrogen in the cambial region were not related to ring width. During June and July, the concentrations of these substances were generally higher at the stem bottom in the pruned F-trees than in the F-trees. The results provide evidence that it is the activity of the cambium rather than the availability of carbohydrates that determines the allocation of wood production along the tree stem. The results also indicate that tracheid production is not directly related to the IAA concentration in the cambial region.  相似文献   

5.
We investigated the interaction between indole-3-acetic acid (IAA) and ethylene in the regulation of the seasonal periodicity of tracheid production in 1-year-old balsam fir (Abies balsamea (L.) Mill.) cuttings collected at different times during the dormant period. The cuttings were left with their buds intact or were debudded and treated either apically with IAA or 2-chloroethylphosphonic acid (Ethrel) in lanolin, laterally with IAA or Ethrel in lanolin, or basally with Ethrel, Co(2+) or Ag(+) in deionized water. The treated cuttings were then cultured for up to 5 weeks under controlled environment conditions favorable for cambial growth. No change in ethylene evolution was detected during the rest-quiescence transition, when IAA-induced tracheid production increased. The induction of cambial reactivation by IAA was associated with a rise in ethylene evolution, but there was no consistent relationship among IAA concentration, tracheid number and ethylene emission. Neither Ethrel, Co(2+) nor Ag(+) affected tracheid production when applied basally, except for 10 and 100 micro M Ethrel and 100 micro M Co(2+), which were inhibitory. In contrast, ethylene evolution was promoted by Ethrel and inhibited by Co(2+), whereas Ag(+) had no effect. Similarly, applying Ethrel apically or laterally increased ethylene evolution, but did not promote tracheid production except in the treatment in which 1 mg Ethrel g(-1) lanolin was applied laterally to cuttings treated apically with 0.1 mg IAA g(-1) lanolin, and in the treatment in which 10 mg Ethrel g(-1) lanolin was applied laterally to budded cuttings. We conclude that (1) ethylene evolution is not specifically associated with IAA-induced tracheid production, (2) ethylene does not mimic the promoting effect of IAA on tracheid production, and (3) ethylene can promote tracheid production, but only when its application results in a localized unphysiologically high concentration in the cambial region, which, in turn, induces an accumulation of IAA.  相似文献   

6.
内源激素含量与银杏叶中类黄酮含量的关系   总被引：1，自引：0，他引：1  
对银杏叶丛枝叶中内源激素和类黄酮含量进行全周期测定。结果表明 :早期脱落酸 (ABA)含量低 ,但在7月初有一次绝对值较低的含量峰 ,8月底后含量迅速上升 ,在 11月初达到含量最大值 ,含量峰与叶中类黄酮峰同步 ;乙烯 (ETH)在 7月初和 9月底形成 2次高峰 ,第 2次峰值较大 ,第 1次峰与叶中类黄酮峰平行 ,第 2次峰超前 ;细胞激动素 (CTKs)含量早期高 ,后波动次数较多 ,玉米素 (Zrs)与CTKs含量变化曲线极显著相关 ;赤霉素 (GA)含量早期较高 ,中后期含量较低 ,在 7月中旬、9月底 2次达到含量低谷 ;吲哚乙酸 (IAA)含量在 5月中旬、8月中旬、9月底出现 3次含量高峰 ,第 1次峰值最大 ;较高的ETH、ABA含量 ,较大的CTKs IAA值 ,较低的GA含量有利于叶类黄酮合成 ;在最低的IAA ABA、IAA ETH、CTKs ABA、CTKs ETH、GA ABA、GA ABA、GA ETH值时 ,相应地在银杏叶中有类黄酮合成高峰。讨论了内源激素与叶中类黄酮之间的关系。  相似文献   

7.
Selected wood and cell characteristics were examined in incrementcores from two 46-year-old pines that had been fertilized withammonium sulphate 37, 38 and 39 years after planting. Fertilizationincreased the ring-width and greatly reduced the latewood percentand the bulk density of both early and late wood; the effectswere greatest shortly after the last application of fertilizer,but remained apparent for at least five further years. Thoughboth trees produced more early wood cells only one of the twoproduced more latewood. The average tracheid diameter was not changed, though its rangewithin the annual ring was increased. There were decreases intracheid wall-thickness and length, and in wall volume per tracheid.These changes were greatest in latewood, so that the differencebetween early and latewood was reduced, while the characteristicsof the earlywood were exaggerated. Resin canal radial (but nottangential) diameter and cross-sectional area increased, thoughnumber of canals per unit area of ring was unchanged. Correlations with temperature, insolation and rainfall in March-Juneand July-October suggest that (1) wood properties are influencedby the weather of both the current and the previous growingseasons; (2) the climatic optima for the fertilized and unfertilizedtrees are different and consequently (3) the weather influencesthe effect of fertilization on wood properties.  相似文献   

8.
The relationship between radial growth and assimilate movement was determined in one-year-old Pinus sylvestris (L.) cuttings collected during the dormant period and reactivated for 1-27 days under environmental conditions favorable for growth. The cuttings were either left with buds intact, defoliated along the distal 8 cm, or debudded and treated apically with 0 or 1 mg g(-1) indole-3-acetic acid (IAA) in lanolin. Radial growth was measured as tracheid production and bark radial width. The distribution of (14)C-photosynthate 1 or 5 days after exposure to (14)CO(2) was used to indicate assimilate movement. Debudding inhibited tracheid production and decreased acropetal (14)C-photosynthate transport, whereas applying IAA to debudded cuttings promoted both these processes and, in addition, induced vigorous callus growth within the bark immediately below the application point. Distal defoliation markedly increased the amount of (14)C-photosynthate transported toward the apex without altering how debudding and exogenous IAA affected tracheid production and the distribution of (14)C-photosynthate. The production of tracheids induced by apically applied IAA in debudded and distally defoliated cuttings increased progressively in material collected on September 9, October 14 and November 24, whereas bark radial width and acropetal (14)C-photosynthate movement increased only between the first two collection dates. Ringing midway between the IAA source and the bottom of the distally defoliated region with a lanolin mixture of 10 mg g(-1)N-1-naphthylphthalamic acid (NPA), 1 mg g(-1) methyl-2-chloro-9-hydroxy-fluorene-9-carboxylic acid (CF) or 10 mg g(-1) phenylacetic acid (PAA) reduced radial growth and [1-(14)C]IAA transport below the ring and locally promoted radial growth and accumulated radioactivity above. (14)C-Photosynthate transport into the region above the ring either was not altered (CF, PAA) or was increased (NPA). The results indicate that apically applied IAA induces the acropetal movement of (14)C-photosynthate in debudded P. sylvestris shoots by locally promoting activity correlated with tracheid and callus production rather than by affecting radial growth or phloem transport processes, or both, at a distance below the IAA source.  相似文献   

9.
We analyzed annual carbohydrate storage and mobilization of bearing ("on") and non-bearing ("off") 'Kerman' pistachio (Pistacia vera L.) trees growing on three different rootstocks. On all rootstocks, carbohydrate storage in shoots and branches of "on" and "off" trees was lowest following the spring growth flush. In "off" trees, stored carbohydrates increased and remained high after the initial growth flush. In "on" trees, stem carbohydrates increased temporarily in early summer, but were mobilized in mid-season during kernel fill, and then increased again after nut harvest. During the dormant season, the only substantial differences in carbohydrate storage between previously "on" and "off" trees were found in the roots of the weakest rootstock. The annual carbohydrate storage and mobilization pattern in canopy branches of heavily cropped pistachio trees appeared to be driven by carbohydrate demands related to nut development and untempered by tree vigor. Mobilization of carbohydrates from current-season and 1- and 2-year-old stem wood of "on" trees during the primary period of kernel fill corresponded with the period of inflorescence bud abscission. Thus, the alternate bearing pattern associated with inflorescence bud abscission in 'Kerman' pistachio may be a function of mid-season mobilization of stored carbohydrates in current-season stems resulting in stimulation of inflorescence bud abscission.  相似文献   

10.
The fast growth of Tetracentron sinense is a potential valuable timber resource, but whether its anatomy and chemical components are suitable for timber is unknown. We used light microscopy and SEM to examine the anatomical structure and FITR to measure the chemical components of the phloem and xylem of this tree. Radial variations in growth ring width and tracheid dimensions were also evaluated. The sieve tube, phloem parenchyma cell and sclereids clusters were the main cells in phloem, and the tracheid was the fundamental cell in xylem. An unusual tracheid type, fiber-tracheids or vessel-liked elements was visible. Wood rays nonstoried, uniseriate and multiseriate, including heterogeneous II, occasionally I, and usually 3–6 cells wide. The mean growth-ring width was 2.53 ± 0.46 mm, and the percentage of late wood was over 60%. For radial variation, growth-ring width increased at an early growth stage, and reached the largest increment during years 11–15, then decreased. The maximum growth-ring width was 5.313 mm. During late growth (60–85 years), trees also maintained a high radial growth increment. Radial variation in the percentage of late wood was uniform, about 50–70%, throughout the growth years. Growth patterns in the length and width of early and late wood were similar as the trees aged. From the FTIR results, the chemical components differed significantly between xylem and phloem, hemicellulose in particular was higher in the xylem than in the phloem, where it was apparently absent. All of these suggest that the composition of phloem in T. sinense is very similar to that of hardwood, and it has higher growth ratio and uniform wood properties.  相似文献   

11.
Variation in the number and diversity of bark beetles in spaced mature lodgepole pine stands in the East Kootenay region of British Columbia was analyzed in relation to location (site), spacing treatment and years following treatment. We analyzed the number of bark beetles and the number of bark beetle species that emerged from stumps or were captured in flight traps in the first five years following spacing. We also investigated the incidence of bark beetle attacks on the remaining trees and the mean dates of emergence from stumps and of capture in flight traps for the common species. Observations were made on three sites, each having three treatments: 4 m × 4 m spacing, 5 m × 5 m spacing, and an untreated control. The mean density of bark beetles emerged from stumps was different among sites and years but not between spacing treatments. There was no statistically significant variation in the number of bark beetle species captured in flight traps by site, spacing treatment, years, or spacing treatment and years. Significantly more bark beetles were captured in the 4 m × 4 m spacing treatment than in the control. The number of bark beetles captured was the highest in the first 2 years following treatment. Up to 26 species of bark beetles, excluding ambrosia beetles, were captured in flight barrier traps. There was no difference in species diversity by site or treatment indicating that species diversity in mature lodgepole pine is relatively stable over large areas. Of the 213 trees that sustained at least 10 attacks by bark beetles on the lower 2 m of the bole, 59.1% occurred in the spaced plots but only 18.2% of those were successful, versus 74.7% success in the infested trees in the control plots. The majority of infested trees contained Ips sp., Dendroctonus valens and D. murrayanae. Of the seven trees attacked by mountain pine beetle (D. ponderosae) only one tree was located in a spaced plot.  相似文献   

12.
Wang Q  Little CH  Odén PC 《Tree physiology》1997,17(11):715-721
We investigated the involvement of gibberellins (GAs) and indole-3-acetic acid (IAA) in the control of longitudinal and cambial growth in current-year shoots of Pinus sylvestris L. Elongating terminal shoots, located at the apex of previous-year (1-year-old) branches in the uppermost whorl on the main stem, were variously decapitated (apical 5 to 10 mm removed), defoliated (all developing needle fascicles removed) and treated with endogenous GA(4/7) or IAA, or both. Shoot length and the radial widths of xylem and phloem were measured, and the concentrations of GA(1), GA(3), GA(4), GA(9) and IAA in the stem were determined by combined gas chromatography-mass spectrometry with deuterated GAs and [(13)C(6)]-IAA as internal standards. Decapitation decreased the production of xylem and phloem and the IAA concentration, but did not alter either longitudinal growth or the concentrations of GAs. Defoliation markedly inhibited shoot elongation, as well as cambial growth, and reduced the concentrations of GA(1), GA(3), GA(4), GA(9) and IAA. Application of GA(4/7) to defoliated shoots promoted longitudinal growth and phloem production, without affecting xylem production or IAA concentration. Application of GA(4/7) and IAA together to decapitated + defoliated shoots increased shoot elongation, xylem and phloem production and IAA concentration, whereas applying either substance alone had a smaller effect or none at all. We conclude that, for elongating current-year shoots of Pinus sylvestris, (1) both the shoot apex and the developing needle fascicles are major sources of the IAA present in the stem, whereas stem GAs originate primarily in the needle fascicles, (2) GAs and IAA are required for both shoot elongation and cambial growth, and (3) GAs act directly in the control of shoot growth, rather than indirectly through affecting the IAA concentration.  相似文献   

13.
‘Zhongqiusucui’ jujube secondary shoots were treated with 3-indolebutyric acid (IBA) at three concentrations, 500, 1000 and 1500 mg/L. Results show that IBA could significantly enhance rooting and root characteristics of cuttings and were best with IBA at 1500 mg/L. In the rooting process, the formation of adventitious roots was related to the consumption and accumulation of nutrients (soluble sugars and proteins) and the changes in endogenous hormones in phloem, leaf tips and leaf bases. The rooting of cuttings had a positive correlation with the consumption of soluble sugars during the period of callus formation and with the accumulation of soluble sugars during adventitious root formation and growth. Rooting was positively related to the breakdown of soluble proteins in the phloem when the callus formed, and had a positive correlation with its accumulation during adventitious root formation and growth. Leaf tips and leaf bases showed a reverse trend in changes of soluble protein. However, together with the phloem, leaf tips and leaf bases regulated and controlled the formation and development of adventitious roots. The main activities of soluble proteins exist in the leaf tips as this was the main source of soluble proteins. The relation between rooting and IAA (indole-3-acetic acid) content in phloem was positive and thus a high concentration of IAA could benefit the induction and formation of adventitious roots. However, rooting was negatively related with ABA (abscisic acid) and GA (gibberellic acid) and a high concentration of both could inhibit the induction and formation of adventitious roots. Rooting had a positive correlation with phloem IAA/ABA ratios, and higher ratios could improve rooting. Low concentrations of ZR (zeatin riboside) triggered the induction of adventitious roots, while higher concentrations promoted root growth. Endogenous hormones in leaf tips and bases had an impact on rooting. The activities of endogenous hormones mainly existed in leaf tips because they play a major role in the production and consumption of IAA and its ABA content increased during rooting. The ZR in leaf tips influenced the rooting of cuttings, especially in the callus formation and rooting stage. Leaf tips were the main source of GA.  相似文献   

14.
Prescribed fire is used in the Sudanian savanna-woodland of West Africa as a forest management tool. An experiment was carried out to assess the effects of season of burning, and different vertical probe positions on maximum fire temperature and temperature residence time above 60°C which is considered lethal for plant tissues. Seasons of burning considered were: an early season fire set at the beginning of the dry season (beginning of December), mid-season fire set at the peak of the dry season (mid-January), and a late season fire at the end of the dry season (end of March). The effects of these fires on the germination of buried seeds of three socio-economically valuable tree species were also examined. Results indicated significant differences in maximum fire temperature and residence time with respect to season of burning and vertical probe position (p < 0.001). The highest and longest lasting temperatures were observed at 20 cm above ground during early fire and at the soil surface during mid-season and late fires. This, in turn, affected germination responses of seeds buried at different soil depths. Implications of these findings in the current management practices are discussed.  相似文献   

15.
The relationships between bending properties, compressive strength, tracheid length, microfibril angle, and ring characteristics of 20-year-old Taiwania (Taiwania cryptomerioides Hay.) trees were examined. The trees came from different thinning and pruning treatments, but the practices showed no significant effect on the investigated properties. The results showed that based on comparison with the literature, plantation-grown immature Taiwania have noticeably lower average strength properties than mature trees of the same species. Wood density and bending and compressive strengths were not related to either tracheid length or microfibril angle in young Taiwania. There were positive relationships between bending strength and compressive strength. The wood density, ring width, earlywood width, earlywood density, and latewood percentage were the most important predictors of strength by simple linear regressions. The wood density and ring width/earlywood width may be considered as indicators for assessing the bending strength, while wood density and latewood percentage were the best predictors of compressive strength by multiple linear regressions.  相似文献   

16.
关于激素在果实生长发育过程中的作用 ,前人曾进行过大量的研究 ,并取得了许多宝贵的成果[1,2 ] ,而对银杏 (ＧｉｎｋｇｏｂｉｌｏｂａＬ .)种子的相关研究却很少。银杏作为一种古老的裸子植物 ,其种子的生长发育与一般的裸子植物又有不同 ,它的胚珠直接着生在短枝上 ,没有了一般裸子植物的球果构造 ,从表面上看很类似于杏 (Ａｒｍｅｎｉａｃａｓｐｐ .)、桃 (Ａｍｙｇｄａｌｕｓｓｐｐ .)等的生长发育过程。本文从分析银杏种子生长发育的一般特点出发 ,研究了银杏种子生长发育与内源激素含量的关系 ,旨在探索银杏种子生长发育的一般规律 ,…  相似文献   

17.
火炬松不同种源纸浆材材性的变异   总被引：1，自引：0，他引：1  
1983年火炬松31个种源引种栽培在浙江富阳中国林业科学研究院亚热带林业研究所实验林场,研究表明该批种源间10年生树木生长量和纸浆材材性因子如晚材率、管胞形态特征值(管胞长度、宽度、腔径、壁厚、长宽比、腔径比、壁腔比)、管胞S2层微纤丝角和木材基本密度存在着显著差异,木材主要化学成分中纤维素和木素含量种源间存在着显著差异,而戊聚糖和苯醇浸提物含量种源间差异不显著.这些材性特征除了木材化学性状因子外,均受中等以上程度遗传控制.木材纤维素、木素、戊聚糖和苯醇浸提物含量的广义遗传力分别为0.088、0.003、0.340和0.307,其余性状广义遗传力均大于0.50.引种地栽培环境对木材性状有显著影响.种源原产地纬度与树木生长量、管胞宽度、管胞直径和管胞微纤丝角呈负相关,与晚材率、木材密度呈正相关.31个种源树木胸高直径与管胞长宽比、管胞壁腔比、木材密度呈显著负相关,与管胞宽度、管胞直径、管胞腔径比呈正相关.  相似文献   

18.
Budget studies have shown that internal cycling may contribute a large proportion of the annual nutrient supply required to support new growth in trees. Use of budgets to quantify internal cycling only quantifies the net transfer of nutrients within the plant. Differential partitioning of remobilized nutrients and current nutrient uptake could lead to errors in the interpretation of results from these studies. We have quantified the dynamic relationships among tree growth, nutrient uptake and internal cycling by labeling the current uptake of N in trees that received contrasting amounts of nutrient. Two-year-old seedlings of Sitka spruce (Picea sitchensis (Bong.) Carr.) were grown in sand culture in a greenhouse for one year. The trees received nutrients in a balanced solution at either a high (high-RAR) or a low (low-RAR) relative addition rate throughout the experiment. Current N uptake was labeled with (15)N from April 13 to July 25. Thereafter, trees were re-potted in clean sand and unlabeled N applied until November 13. Overall growth was sustained for approximately 10 weeks before treatment effects were observed. Initially, no differences in the partition of growth or remobilized N occurred, although partition of current uptake favored the roots of plants in the low-RAR treatment. After 6 weeks, the partition of both growth and remobilized N altered in favor of roots of plants in the low-RAR treatment. Nutrient supply had no effect on the amount or rate of N remobilization. No evidence was found to suggest that N taken up in the current season and partitioned to preexisting shoots or roots is remobilized late in the season to support growth of new shoots. However, some trees in the high-RAR treatment exhibited a second flush of growth later in the season that was partially sustained by remobilization of (15)N from current shoots formed earlier in the season. Use of (15)N demonstrated differential partitioning of current uptake and remobilized N. The results highlight the limitations of simple budget studies for quantifying internal cycling.  相似文献   

19.
骏枣果实中的内源激素含量与其生理落果的关系   总被引：1，自引：0，他引：1  
为给枣花果管理和生长期调控等提供理论依据和实践指导,以骏枣为研究对象,利用高效液相色谱法测定了骏枣果实发育过程中其正常果与脱落果中内源激素赤霉素(GA3)、生长素(IAA)、玉米素(ZT)和脱落酸(ABA)的含量,并结合骏枣生理落果规律探讨了骏枣果实中的内源激素含量与其生理落果的关系。结果表明:在幼果期和果实膨大后期,骏枣分别出现了2个落果高峰期,第1次生理落果高峰的形成与枣果中GA3、IAA含量的过低有关;第2次落果高峰发生在果实膨大后期,此期枣果即将成熟,枣果中的GA3、IAA和ZT已大量减少,而ABA却急剧上升;文中比较分析了正常果与脱落果中促进与抑制生长两类激素比值的变化曲线,结果发现,在枣果的整个发育时期,其抑制生长激素ABA一直维持在较高水平上,脱落果中的含量相对较多,正常发育果中ABA/(GA3+IAA+ZT)之值则始终处于相对平稳的状态中,枣果中抑制生长与促进生长两类激素的比值,对骏枣生理落果有着调控作用,当其ABA/(GA3+IAA+ZT)的比值不平衡时,ABA含量过高,而促进生长物质(GA3+IAA+ZT)的含量降低,这也会导致骏枣生理落果现象的发生。  相似文献   

20.
广西融水特色红心杉木优树材质性状变异规律研究   总被引：2，自引：0，他引：2       下载免费PDF全文
[目的]通过测定和分析广西融水种源红心杉木优树材质性状指标,以了解该地区红心杉木材性状变异规律。[方法]以广西融水种源60株20年生的红心杉木优树为研究材料,测定单株材积、红心率、基本密度、组织比量、管胞性状、微纤丝角等10个材质性状指标,分析各材性性状指标分布和变异规律及性状间的相关关系。[结果]表明:红心率、基本密度、木射线比量、管胞比量、管胞长、管胞宽、管胞长宽比等性状数据分布服从正态分布。融水两个地区红心杉优树轴向薄壁细胞比量的变异系数分别为35.08%和44.97%,变异较大。管胞比量变异系数分别为3.28%和3.56%,变异较小。红心率、木射线比量、管胞长、管胞宽、微纤丝角等性状差异极显著(P0.01),轴向薄壁细胞比量差异显著(P0.05)。10个材质性状间存在12对表型显著相关。[结论]测定的10个性状均是连续性数量性状。早、晚材的管胞长度、管胞宽度和管胞长宽比等性状数据呈从心材至边材逐渐增加的规律。作为重要经济性状的红心率与木射线比量呈极显著正相关(P0.01),单株材积与轴向薄壁细胞比量呈显著正相关(P0.05),而单株材积与基本密度的相关性不显著,这使红心杉木生长量与材性相结合的遗传改良成为可能。  相似文献   

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