水麻扦插的插穗类型与扦插时间效应分析

[目的]分析水麻扦插的插穗类型与扦插时间效应。[方法]通过对水麻夏季扦插与冬季扦插的插穗类型、嫩枝扦插时间的析因试验,分析水麻扦插的插穗类型与扦插时间效应。[结果]插穗类型和嫩枝扦插时间对水麻扦插生根率影响均达极显著水平(P0.01)。其中,夏季扦插2年生插穗生根率明显高于1年生带顶芽插穗及1年生不带顶芽插穗的生根率;1年生带顶芽与1年生不带顶芽插穗的扦插生根率差异不显著(P0.05);冬季扦插1年生带顶芽插穗及1年生不带顶芽插穗的生根率显著高于2年生插穗生根率(P0.05);6月下旬到7月中旬的扦插生根率显著高于其他时间的扦插生根率(P0.05),这时期穗条处于半木质化状态。[结论]水麻嫩枝扦插和硬枝扦插、夏季和冬季扦插均可以在生产中采用。     

柱型苹果在生根培养中的组培特性研究

[目的]为研究苹果地上部的生长发育提供参考。[方法]以‘富士’ב特拉蒙’杂交后代的柱型和非柱型株系茎尖为试材,对2种株系苹果茎尖进行茎尖培养、扩繁培养、生根培养,茎尖萌发培养基为MS+1.5 mg/L 6-BA+0.1 mg/L NAA,扩繁培养基为MS+1.0mg/L 6-BA+0.1 mg/L NAA,生根培养基为MS+1.0 mg/L 6-BA+0.1 mg/L NAA+0.5 mg/L IBA,并在适宜条件下移到水培完全营养液中对2种树型苹果的根部性状进行了比较。[结果]柱型苹果成活率较高,染菌率较低,增殖系数高,根的生根率、生长速度、主根长度和侧根数量均优于非柱型苹果。[结论]柱型性状是苹果育种上可利用的优良性状之一。     

毛白杨转基因植株的研究

毛白杨转基因植株的研究郑均宝，王峰，刘群录（河北林学院保定０７１０００）卜学贤，陈维伦（中国科学院植物研究所北京１０００４４）关键词毛白杨，Ｒ１０００和Ｒ１０００（ＰＴＶＫ８５），生根能力，生长量，形态变化农杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍ）对植物的...     

A comparison of pre-planting treatments on hardwood cuttings of four hybrid poplar clones

Rooting and early growth of four hybrid poplar clones (Populus spp.) planted in a greenhouse were examined after applying 40 pre-rooting treatment combinations to dormant cuttings. Treatments included 2 cutting lengths (5 and 10 cm), 5 soaking times (0, 2, 4, 8, and 12 days), and 4 dips (chitosan, rooting hormone powder, liquid rooting hormone added to the soaking water, and none). Significant differences in both rooting percentages and growth were shown between clones after 7 weeks of growth. Ten cm cuttings had 29% greater rooting success, 28% more above-ground growth, and 12% lower root/shoot ratios than 5 cm cuttings. Cuttings planted without soaking had the lowest rooting success, at less than 45% on average. Commercial rooting hormones decreased the number of rooted cuttings but increased root/shoot ratios. For optimal rooting, we recommend using 10 cm cuttings, soaked for 2 days in water (4 days for the Jackii10 clone) without any additional dipping/hormone substance.     

笃斯越桔嫩枝扦插繁殖技术

采用笃斯越桔嫩枝扦插。用生根剂处理插穗，并在不同的基质上进行扦插的试验结果表明，嫩枝扦插以河沙作为基质最好，用生根剂ABT处理的插穗生根率最高，以ABT 1mg/L、NAA 1mg/L和IBA 1mg/L效果最佳。     

毛白杨嵌合体扦插生根相关理化特性分析

对自宁晋县获得的毛白杨嵌合体扦插生根过程的动态跟踪分析表明，嵌合体过氧化物酶活性在扦插初期呈上升趋势，第5d升至高峰，之后下降，第7d至低谷，第17d又出现一高峰，而毛白杨没有此规律，并且前期与此恰好相反；酚类、黄酮类物质与过氧化物酶活性变化相似，也有两个高峰，毛白杨中变化与嵌合体相反，且含量高于嵌合体；吲哚乙酸氧化酶活性变化规律与过氧化物酶刚好相反。试验证明嵌合体易生根与过氧化物酶活性、吲哚乙酸氧化酶活性及酚类、黄酮类含量密切相关，是协同作用的综合结果，而毛白杨不易生根也恰好是不能满足这些要求。     

Metabolic changes during adventitious root primordium development in <Emphasis Type="Italic">Tectona grandis</Emphasis> Linn. f. (teak) cuttings as affected by age of donor plants and auxin (IBA and NAA) treatment

Aging of the donor tree decreased adventitious root formation in shoot cuttings of Tectona grandis Linn. f. (teak). Exogenous application of auxins, i.e., α-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA) has a significant positive effect on the percentage of rooting. The maximum percent rooting was obtained with 4,000 ppm IBA as compared to other treatment. Significant increase in root number was recorded in shoot cuttings treated with 4,000 ppm NAA. The overall rooting response was better in the treatment with IBA rather than with NAA. Further periodic samples (0, 10, 20, and 30 days) were taken to assess the total soluble sugar, starch, protein, and peroxidase (PER) activity in the rooting zone of shoot cuttings of teak during adventitious root formation. Application NAA and IBA to shoot cuttings resulted in an increase in the level of total soluble sugar, starch, protein, and PER-activity in the rooting zone. The stored carbohydrates were utilized during adventitious root formation. Hence, total soluble sugar and starch contents of cuttings, irrespective of age of donor plants, decreased with the passage of time in cuttings planted for rooting. Significant fluctuations were observed in the protein content of cuttings during the time of root induction. There was an increase in the protein content with the passage of time from the day of planting up to its 20th day, followed by a sharp decline in the protein content of cuttings at the 30th day of planting, irrespective of the age of donor plants or the treatment of cuttings with auxins. Irrespective of donor plant age, PER-activity in the cuttings increased from the day of their planting for rooting up to the 20th day, and then declined at its 30th day of planting. It was interesting to note that PER-activity remained higher at all stages in the cuttings of 2-month-old seedlings which rooted profusely as compared to the cuttings of 15- and 30-year-old donor plants those rooted poorly. This study suggested that the exogenously applied NAA and IBA at different concentration seems to activate sugar metabolism for release of energy, protein and PER-activity which are necessary for cellular division and differentiation during adventitious root primordium initiation or development in the rooting zone of shoot cuttings.     

鹅掌楸组织培养技术初探

鹅掌楸外植体是以种子发芽后的无菌苗为材料。通过实验结果分析，利用基本培养基MS(以下简称MS)添加适当的细胞分裂素可以促进种子的发芽。在初步培养中，以WPM 0．5mg／L(单位下同)BAP 0．1NAA培养基分化最好。在继代培养中，以MS 0．2BAP 0．05NAA培养基中不定芽诱导情况最好。不定芽在接入生根培养基20d后，其高度平均可长高1．86cm。在生根培养中，以1／2MS 0．2IBA 0．1NAA 0．1ABT较好，其生根率达到了60％左右。     

Effects of resource plant size on rooting of <Emphasis Type="Italic">Dryobalanops lanceolata</Emphasis> cuttings

 Cuttings from older trees of the Dipterocarpaceae generally lose their ability to root. However, branches in a canopy of adult dipterocarps are a possible source of cuttings because they show juvenile characteristics in architecture due to “adaptive reiteration”, suggesting physiological rejuvenation. Effects of resource plant size on the rooting of cuttings and the possibility of using cuttings from reiterated branches of adult trees were studied for Dryobalanops lanceolata, an emergent dipterocarp species. A cutting experiment with non-mist propagators was conducted for cuttings collected from resource plants of four different size classes: <2 m, 2–5 m, 8–15 m, and 70 m in height. The smallest size class included two different age classes: <2 and >2 years old. Cuttings from the tallest resource plant were collected from reiterated branches. Rooting percentage was negatively correlated with resource plant size: 77–78% for resource plants <2 m, 63% for 2–5 m, 36% for 8–15 m, and 0% for 70 m. Rooting percentages of cuttings collected from different individuals were not different for the 2–5 m tall class, while they were significantly different for the 8–15 m tall class. Resource plant size was negatively correlated with the number of roots for rooted cuttings. No significant relationship was observed between resource plant size and mean length of each root, total root length or total root dry weight for rooted cuttings. The results suggest the possibility of collecting cuttings from relatively large resource plants up to 15 m tall and >20 years old if we chose good individuals for resource plants. The results, however, show the difficulty in using reiterated branches of adult trees as a source of cuttings for D. lanceolata. Received: October 15, 2001 / Accepted: November 11, 2002 Acknowledgments We express our sincere thanks to Dr. S. Tamura, Dr. K. Ogino, and Mr. A.A. Hamid for their kind support. The tree tower was constructed in a cooperative project between Japan and Sarawak supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan (Grant NP0201). The cutting experiment was partly funded by the Nippon Life Insurance Foundation and the Japan Society for the Promotion of Science (JSPS-RFTF96R16001). Correspondence to:A. Itoh     

Root development across a chronosequence in a Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis> D. Don) plantation

We investigated the biomass, vertical distribution, and specific root length (SRL) of fine and small roots in a chronosequence of Japanese cedar (Cryptomeria japonica D. Don) plantations in Nara Prefecture, central Japan. Roots were collected from soil blocks up to 50 cm in depth in five plantations of differing age: 4, 15, 30, 41, and 88 years old. Fine-root biomass reached a maximum (639 g m₋₂) in the 15-year-old stand before canopy closure, decreased in the 30-year-old stand (422 g m₋₂), and thereafter was stable. Except in the 30-year-old stand, fine-root biomass increased in deeper soil layers as stand age increased, and the depth at which the cumulative biomass of fine roots reached 90% exhibited a good allometric relationship with mean stem diameter. Both root-length density (root length per unit soil volume) and SRL decreased with soil depth in all stands, indicating that plants mainly acquire water and nutrients from shallow soils. The highest SRL was observed in the 4-year-old stand, but the relationship between SRL and stand age was unclear in older stands. The SRL in surface soils seemed to decrease with increases in root-length density, suggesting that branching of the fine-root system during development is related to density-dependent processes rather than age.