Field performance of micropropagated,macropropagated, and seed-derived propagules of three Eucalyptus grandis ortets

Tree size, survival, and coppicing of micropropagated plantlets, macropropagated cuttings, and seedlings of Eucalyptus grandis Hill ex Maiden were monitored through 57 months in a study in southern Florida to assess propagation options. Two plantlet lines developed by direct micropropagation and orchard open-pollinated seedlings from three ortets were compared in the main study. Rooted cuttings from up to four ramets of each of the three ortets and another ortet were examined in an adjacent supplemental study. Freezes at six and 16 months killed most initial and first-coppice stems to the ground. Most developmental differences in the main study were consistent from ages 2 to 57 months. Propagation by ortet interactions were observed beginning at 21 months, due to the poor performance of seedlings of one ortet after the second freeze. At 57 months, no differences in tree height, DBH, volume, or survival were detected between plantlet lines and between rooted cuttings and plantlets, but seedlings were inferior to plantlets and cuttings. Vegetative propagules had more uniform tree size at every age, with typically less than one-half the variability observed among seedlings. Even though plantlets and cuttings may be more expensive to produce, they have numerous advantages over seedlings for E. grandis plantation establishment in Florida.     

石刁柏胚乳愈伤组织的诱导及植株的再生

石刁柏已形成细胞的幼嫩胚乳,接种在附加有不同浓度的生长素(NAA)和细胞分裂素(BA)的 MS 培养基上,获得了愈伤组织。愈伤组织的诱导频率随生长素的浓度不同而异,可达65.9—83.1%。将胚乳愈伤组织转移到降低了生长素浓度或只含有低浓度生长素的分化培养基上,可陆续分化芽、根、芽丛和少量胚状体,个别的芽和胚状体能发育成小植株。切取1.5—5cm 长的芽,接种在诱导根的培养基上,或在 IBA50ppm 溶液中浸泡2小时,转移到 MS 基本培养基上,部分芽能生根形成完整植株。     

Effect of maturation duration on desiccation tolerance in hybrid larch (Larix×leptoeuropaea dengler) somatic embryos

Summary Cotyledonary somatic embryos ofLarix × leptoeuropaea that developed after various maturation times on media containing abscisic acid showed different frequencies of conversion into plants. Drying of these somatic embryos under high relative humidity (RH) before germination improved plantlet recovery and eliminated differences in the performance of somatic embryos matured for different times. However, dehydration of somatic embryos under 98% RH to a water content below that of zygotic embryos excised from mature seeds (0.97 and 1.36 g H₂O/g dry weight, respectively) showed a strong positive correlation between longer maturation time and desiccation tolerance. Drying somatic embryos at 4° C under 59% RH for 1 wk resulted in desiccation to a water content of 0.30 g H₂O/g dry weight, which was the closest to the hydration state of zygotic embryos in dried, stored seeds (0.20 g H₂O/g dry weight). Under this condition, only somatic embryos matured for 5 wk germinated and produced plantlets at a relatively high frequency (73 and 41%, respectively).     

Factors affecting in vitro clonal propagation of Prosopis cineraria

Genotype, age of tree, nature of explant and size (length and diameter), season of explant collection, explant position on medium, plant growth regulators and certain additives (ascorbic and citric acids, adenine sulphate, L-arginine, glutamine and ammonium citrate), incubation conditions, and subculturing period greatly influenced the in vitro clonal propagation of P. cineraria. The maximum number of 10–12 shoots were induced from the nodal shoot segment from pruned thorny adult trees on Murashige and Skoog's (MS) medium containing 0.1 mgl^-1 indole- 3-acetic acid (IAA)+2.5 mgl^-1 benzylaminopurine (BAP)+additives. Higher temperature (31+-2°C) and mixed (fluorescent and incandescent) light of 50 mol m^-2 s^-1 photon flux density for 12 h per day photoperiod favoured shoot induction and subsequent growth. Explants from thornless trees produced 6–8 shoots per explant on MS medium containing 0.1 mgl^-1 IAA+5.0 mgl^-1 BAP + additives. Nodal shoot segments obtained from root and stump sprouts produced multiple shoots. Root segments differentiated into multiple shoots on MS medium containing 0.5 mgl^-1 indolebutyric acid (IBA)+2.5 mgl^-1 BAP.Differentiated shoots multiplied best on MS medium containing 0.1 mgl^-1 naphthalene acetic acid (NAA)+1.0 mgl^-1 BAP + additives. To yield multiple shoots the original explant was transferred 6 times on fresh medium after harvesting the differentiated shoots. Shoots were rooted by pulsing with 100 mgl^-1 IBA for 4 h and then culturing on hormone-free half strength MS medium. Initial dark incubation for 5 days at high temperature (33±2°C) was found essential for root induction from shoots which was 63% within two weeks. The rooted plantlets contained a consistent number of chromosomes (2n=28). It is suggested that the protocol developed could be useful for cloning of mature and tested trees of P. cineraria.     

A scanning electron microscope study of normal and vitrified leaves from Datura insignis plantlets cultured in vitro

The surface anatomy of normal and vitreous leaves of plantlets obtained from Datura insignis Barb Rodr nodal segment cultures was compared using scanning electron microscopy. Normal and vitrified leaves are similar in several ways. They are both amphistomatic, and have similar distributions of glandular and non-glandular trichomes. Stomata have similar length, diameter and distribution in normal and vitreous plants. Immature stomata, which have closed pores, and plugged stomata, which contain an amorphous material between their guard cells, occur in both normal and vitrified leaves. Normal and vitreous leaves differ in the frequency of normal and abnormal stomata. Normal stomata have kidney-shaped guard cells and resemble closely those found in field-grown plants, whereas abnormal stomata have deformed guard cells. Normal stomata represent approximately 80% of the total number of stomata in normal leaves, but only 7% of the total number of stomata in vitreous leaves. Abnormal stomata represent 90% of the total number in vitreous leaves. The deformation of guard cells could possibly be a mechanical impediment to stomatal function.     

禿杉组织培养研究

本文详细报道了从秃杉(Taiwania flousiana Gaussen)离体胚诱导不定芽、不定根及从无菌苗茎端培养再生植株的过程。诱导不定芽要求较低的蔗糖浓度(以3％最好);同时BA是必须的,在附加0.1—3 mg/1 BA的White培养基上,从离体胚的子叶或胚轴上诱导了不定芽的发生(以1 mg/1最好);NAA与BA结合使用,对不定芽诱导无促进作用;适当提高光照有利于不定芽的诱导。在诱导不定芽的同时,在子叶表面还观察到有许多无结构的“不定突起”。不定芽起源于子叶表皮下1—2层细胞。IBA对诱导离体胚上产生不定根效果较好。在有或无生长素的培养基上,从生长1月龄的无菌苗茎端培养获得了不定根的产生,在加有细胞分裂索的培养基上,从无菌苗上产生了腋芽。     

植物激素对砀山酥梨脱病毒苗增殖生长的影响

砀山酥梨脱病毒苗培养基中添加外源激素能通过调节内源激素的含量,从而控制脱病毒苗的增殖和生长。苄基腺嘌呤(benzyladen ine,BA)处理可提高脱病毒苗内源玉米素核苷(zeatin riboside,ZR)含量,而脱病毒苗的有效增殖芽数与IAA/ZR比值呈显著负相关;1萘-乙酸(1-naphthalene acetic ac id,NAA)处理可显著提高内源吲哚乙酸(indole acetic ac id,IAA)含量,较高的内源IAA含量有利于芽梢的生长;继代组培苗体内含有一定量的内源赤霉素(G iberllic Ac id,GA1 3),适量的外源GA3处理,可提高内源GA1 3含量而显著降低脱落酸(absc isic ac id,ABA)含量,促进芽梢的伸长和叶面积的扩大。     

Quantitative determination of anti-fungal and insecticide amides in adult plants, plantlets and callus from Piper tuberculatum by reverse-phase high-performance liquid chromatography

A rapid, sensitive and reliable reverse-phase HPLC method was used for the quantitative determination of the anti-fungal and insecticide amides, dihydropiplartine (1), piplartine (2), deltaalpha,beta-dihydropiperine (3) and pellitorine (4) in plants in natura, in plantlets in vitro and ex vitro, and in callus of Piper tuberculatum. Well-resolved peaks were obtained with good detection response and linearity in the range of 15.0-3000 microg/mL. The plants in natura contained compounds 1-4, the plantlets ex vitro and in vitro accumulated compounds 1-2 and 1-4, respectively, while only amide 4 was found in callus.     

Clonal propagation of Acacia catechu Willd. by shoot tip culture

A method is described for in vitromicropropagation through shoot apices of Acaciacatechu Willd., a semi-arid tree valued for Katha (atanin-like substance obtained from red heart wood of10–20 year old trees) and timber. Explants wereexcised from 15-days-old in vitro grownseedlings raised from superior seed stocks. Shoot budinduction from shoot apex explants was observed onMurashige and Skoog's (MS) [12] medium containingvarious growth regulators. A maximum of 12 shoots wasobtained on MS medium supplemented with 1.5 mg/l 6-benzylaminopurine (BAP) and 1.5 mg/l kinetin.Well-developed shoots (3–4 cm long) were rooted on strength MS medium with 3.0 mg/l indole-3-acetic acid (IAA) and sucrose 1.5%. In vitro regenerated plantlets of A. catechu were transferred to field conditions.     

Tuber induction and initiation during production and early field growth of transplants from in vitro-derived potato plants

In transplants from in vitro‐derived plantlets from very early potato (Solanum tuberosum) cultivars, a lower degree of tuber induction at the time of field planting is thought to increase tuber production. Leaf‐bud cuttings were used to assess the progress to tuber induction in in vitro‐derived potato plantlets during the transplant production phase and after subsequent transplanting into the field. Induction and initiation of tubers on the same plants were assessed to study the effects of the duration of transplant production and conditions during transplant production for cv. Gloria (very early) and cv. Bintje (mid‐early). In vitro‐produced plantlets were not induced by the time of planting but rapidly progressed to the induced state thereafter. The progress in induction with time and the change in percentage of plants showing tubers fitted typical sigmoid curves. Plantlets achieved 50% induction ca 15 days after planting into in vivo conditions, and 50% tuber initiation usually occurred 10 days later. Shorter transplant production periods reduced the degree of induction of the transplants at field planting. Transplant production for more than 2 weeks was required to allow conditions during that period to affect induction or initiation. Long‐term non‐inducing conditions delayed the progress to tuber induction in cv. Gloria and delayed tuber initiation in both cultivars. Cv. Gloria showed no faster progress to induction than cv. Bintje but initiated tubers earlier. The results suggest that the relation between progress to induction and tuber initiation is cultivar dependent and that leaf‐bud cuttings can be used successfully in very young in vitro‐derived plants for assessing the progress to tuber induction.