Seasonal dependence of rooting success in cuttings from natural forest trees in Madagascar

Four ligneous species from the tropical forest in the east of Madagascar, with a proven or potentially high economic value, were subject to ‘low-tech’ vegetative propagation tests from stem cuttings. The species concerned were Aphloia theiformis, Ilex mitis, Prunus africana and Ravensara aromatica. The cuttings were three-node segments of stems on which one leaf was retained. All the species proved amenable to rooting. The maximum percentage of rooting ranged from 33% for P. africana to 60% for I. mitis. Rooting success was dependant on the season of cutting (high in the hot season, from October to May, and null in cold season). This study is the first successful attempt at propagating cuttings from Malagasy forest species. This result is of particular importance to P. africana, threatened by destructive exploitation in Madagascar. It goes a step further in the domestication of this species by demonstrating the ability of cutting from 10 year old ortets collected in natural forest to root as it offers the possibility of a reliable and effective method of reintroduction for the species in overexploited zones.     

影响一品红试管苗生根的因素

以一品红旗帜和福星两个品种试管苗为材料,研究了不同因素对试管苗生根的影响。结果表明,生长素种类及其浓度是影响一品红试管苗生根的主要因素,其单独作用以IBA的效果较好,两个品种的适宜浓度分别为0.5和1.0 mg/L。不同生长素配比使用时,两个品种试管苗生根均以1/2 MS+IBA 0.5 mg/L+NAA 0.2 mg/L为好。适当的蔗糖浓度、培养温度及在生根培养前期进行暗培养有利于提高试管苗的生根率。     

外源激素对掌叶大黄愈伤组织诱导及种苗生根的影响

以掌叶大黄无菌苗为材料,研究不同外源激素浓度及配比对试管苗生根、愈伤组织诱导及增殖的影响。结果表明:掌叶大黄的根、茎、叶均可作为诱导愈伤组织的材料。2,4-D诱导愈伤组织的能力明显高于NAA,以2～3mg/L 2,4-D的诱导频率较高为87.93%～93.11%,诱导愈伤组织的适宜培养基为MS+2mg/L NAA+2mg/L 2,4-D+2mg/L 6-BA;6-BA对愈伤组织诱导频率无直接影响,但明显影响愈伤组织的增长量及生长状态。愈伤组织继代增殖以MS+0.5mg/L 2,4-D+1mg/L NAA+1mg/L 6-BA最好;MS+0.5mg/L IBA适宜于试管苗生根。     

紫椴组培快繁技术研究

为探索建立紫椴组织培养快速繁育体系,以紫椴种子为材料,探讨基本培养基、植物生长调节剂浓度及配比对紫椴组培快繁效果的影响。结果表明,增殖培养基以1/2MS培养基最适宜,添加0.05 mg/L 6-BA和0.03 mg/L IBA后,增殖系数可达13.5;MS培养基最适宜做壮苗培养基和生根培养基,最佳壮苗培养基为MS+0.1 mg/L6-BA+0.1 mg/L IBA+0.03 mg/LGA₃,平均苗高达5.15 cm;最佳生根培养基为MS+1.0 mg/L6-BA+0.05 mg/L NAA,生根率达93.3%,生根数达5.7根。     

植物生长调节剂对新几内亚凤仙增殖和生根的影响

以新几内亚凤仙带腋芽茎段为外植体获得无菌苗,研究了6-BA＋NAA组合与KT＋NAA组合对芽增殖的影响,并比较了NAA单独使用与NAA＋MET配合使用对生根的效果。结果表明,KT＋NAA组合的芽增殖倍数要明显低于6-BA＋NAA组合,NAA＋MET组合比NAA具有更好的促进生根效果。因此认为,适合新几内亚凤仙增殖的最佳组合及浓度为6-BA 2.0 mg/L＋NAA0.05 mg/L,芽增殖倍数达到4.57。适合新几内亚凤仙生根的最佳组合及浓度为NAA0.5 mg/L＋MET0.3 mg/L,平均根数为5.37条,平均根长为1.34 cm。     

黄波罗扦插繁殖技术的研究

通过对珍贵树种黄波罗的４个不同类型的插穗进行两次采集并以不同的生根激素、不同的激素浓度和浸泡时间进行扦插正交分析试验，得出了大树伐根当年生萌条经ＮＡＡ５０×１０－６ｍｇ／ｍｌ浸泡６ｈ后，扦插效果最佳。     

Influences of antibiotics on plantlet regeneration via organogenesis in Ioblolly pine （Pinus taeda L.）

Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three Ioblolly pine (Pinus taeda L.) genotypes. Of the antibiotics administered, cefotaxime maximally increased the frequency of callus formation and growth rate of organogeni ccalli, carbenicillin maximally increased the frequency of shoot regeneration and the average number of adventitious shoots per piece of organogenic callus, ampicUlin maximally decreased the rooting frequency of regenerated shoots and mean number of roots per regenerated shoot, in comparison with antibiotic-free media. Compared with the control, ampicillin minimally increased the frequency of callus formation, cefotaxime minimally increased the frequency of shoot regeneration, and carbenicillin minimally decreased the rooting frequency of regenerated shoots in three Ioblolly pine genotypes tested. All three antibiotics increased the frequencies of callus formation and shoot regeneration, and reduced the rooting frequency ot regenerated shoots suggested that the establishment of an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into Ioblolly pine need to select a suitable antibiotic. This investigation could be useful for optimizing genetic transformation of conifers.     

柽柳新品系快繁技术

采用生根粉浸根、利用普通土壤做基质、缩短种条长度和地膜覆盖育苗的方法，可使育苗成活率达到99％，繁殖系数提高3～4倍，找到了一套高效的柽柳繁殖技术，同时降低了育苗成本。     

Propagation ofRobinia pseudoacacia Linn. and Grewiaoptiva Drummond from rooted stem cuttings

Rapid vegetative propagation of promising multipurpose trees is an important need in agroforestry development. Grewia optiva andRobinia pseudoacacia are two such species, about the propagation of which very little is known. The rooting ability of stem cuttings harvested from juvenile (2 year-old) and mature hardwood(15 year-old) trees of Robinia pseudoacacia andGrewia optiva was significantly influenced by the period or season of harvesting cutting. Juvenile cuttings of both species rooted significantly better (42.9% in R. pseudoacacia and 46.6% in G. optiva) than mature hardwood cuttings (34.7% in R.pseudoacacia and 41.4% in G. optiva). The effect was more pronounced in auxin treated cuttings. InR. pseudoacacia, the highest rooting in juvenile(83.3%) and mature (66.6%) cuttings prepared in spring season was observed with the NAA (500 mg/l) treatment. InG. optiva, IBA (250 mg/l) in the monsoon season was most effective and recorded a maximum of 80% and 70%rooting in juvenile and mature cuttings, respectively. The auxin treatments also significantly enhanced the number of roots (23.8 inR. pseudoacacia and 17.6 in G.optiva) and their mean length (14.3 cm inR. pseudoacacia and 16.1 cm inG. optiva). Interactions between age, season and treatments were significant at P < 0.05 level for rooting percent in R. pseudoacacia and non-significant for G. optiva. The results of this study suggest that it is possible to develop clones of genetically superior trees of R. pseudoacacia and G.optiva for use in agroforestry or afforestation programmes. This revised version was published online in June 2006 with corrections to the Cover Date.     

胡椒竹片法快速繁殖技术研究

竹片法胡椒快速繁殖技术的试验表明,以椰糠、土、沙(体积比为1∶1∶1)为扦插基质的成活率最高,达100%;以椰糠和沙(1∶1)作为竹片内填充的生根基质,茎蔓生长快,平均生长速度1.0cm/d繁殖产生的单节插条苗的平均根数、平均根长、平均节间长分别为8条、4.0 cm、6.3 cm。竹片繁殖技术是一种成功的胡椒种苗快速繁殖技术。