用于无核葡萄选育的胚挽救技术研究

通过4a的连续试验,观察了无核葡萄果粒及胚珠发育变化,对胚挽救的多个影响因素包括品种、接种时间、培养基和培养方式进行了研究。结果表明,红脸无核、底来特、黎明无核作母本的胚珠萌发率较高;各品种适宜的接种时间为无核白花后26d,红脸无核花后35d,爱莫无核×火焰无核花后48d,底来特×红宝石无核花后56d;用Nitsch作基本培养基优于B5;添加BA0.2mg/L获得的胚珠萌发率最高;常温黑暗、固体培养有利于胚珠的发育。已定植结果的无核葡萄杂交胚挽救后代的无核比率平均为58.6%。将胚挽救技术用于无核葡萄育种是十分有效的。     

NaCl盐胁迫对番茄种子萌发的影响

对NaCl盐胁迫下番茄种子萌发特性进行了研究和品种间比较,研究了不同浓度盐处理下种子发芽势、发芽率、萌发时间和萌发整齐度、简化活力指数、耐盐指数及幼苗生长的情况.结果表明:盐胁迫下,2个品种番茄发芽势、发芽率、简化活力指数和耐盐指数均呈下降趋势;胚根/胚芽比在低盐浓度时呈现下降趋势,但随浓度增加而呈上升趋势.说明低盐浓度可刺激种子萌发,但在较高盐浓度胁迫下种子活力下降,下降程度的差异说明耐盐性不同;随盐浓度增加,种子的萌发时间延长,萌发整齐度下降,品种不同萌发时间和萌发整齐度不同.     

Some Effects of Seed Size and Maturity on the Yield of Carrot Crops

Carrot seed was harvested on eight occasions from crops grown at Wellesbourne during 1962–64. Seed from each harvest was separated into four size grades by means of round-holed sieves. In laboratory tests, the percentage germination of the seeds increased with increasing seed size. Late-harvested, mature seed of a given size generally had a higher percentage germination than less mature, but otherwise similar, seed. The numbers of seedlings which emerged per 100 seeds sown in the field were linearly related but not directly proportional to the percentage germination of the seed, regardless of seed size or maturity. At comparable plant densities, large seeds gave bigger seedlings than small seeds, and after 15–18 weeks of growth the yield of roots was 15–20% higher from large than from small seed. However, with older crops (24 weeks) no such yield differences were measurable. Graded seed of all but the smallest size gave crops in which the root size had a lower coefficient of variation than that of crops grown from ungraded seed.

In an experiment carried out in 1966 with small, large and ungraded seed from eight imported samples, the results were similar to those obtained with the seed produced at Wellesbourne.

The results suggested that only with crops intended for harvesting when younger than about 18 weeks would greater yields and more uniform roots be expected if graded seed of larger sizes were used rather than small or ungraded seed.     

Seed germinability in Musa velutina Wendl. & Drude is markedly lowered by 1 week in dry-storage

SUMMARY

We investigated the effects of dry-storage of Musa velutina seeds on seed and embryo germination. Seeds were collected immediately after harvest and stored in dry vermiculite at 25°C, in the dark, for 0, 1, 2, or 4 months. The germinability of dry-stored seeds was assessed by incubation in vermiculite at 25°C for 4 months, with 75% [(w/w); –0.01 MPa] moisture content to promote embryo development in viable seeds. Seeds that had not been dry-stored and stored in vermiculite at 75% (w/w) moisture content for 4 months showed 90% germination by 20 d after sowing, but no seeds that had been dry-stored for longer than 1 month germinated. Seeds were also dry-stored at 25°C, in the dark, in Petri dishes for 0, 1, 2, 3, or 4 weeks after harvest and the embryos removed from these seeds were cultured on MS medium. All embryos that had been isolated from seeds at harvest (i.e., 0 weeks in dry-storage) germinated during embryo culture. However, embryos removed from seeds that had been dry-stored for 1 week showed a substantial decrease in both size and germinability. Seeds were also stored at different moisture contents for 4 months after harvest. No seeds that had been stored at 0% moisture content (i.e., dry) germinated, but > 85% of seeds stored at ≥ 25% (w/w) moisture contents germinated. Higher moisture contents increased the uniformity of seed germination, showing that M. velutina seeds rapidly lose their germinability through dehydration, indicating that they are sensitive to desiccation.     

In vitro Germination of Early Ripening Sweet Cherry Varieties (Prunus avium L.) at Different Fruit Ripening Stages

In vitro embryo culture enabled satisfactory germination of immature seeds produced in crosses from early ripening sweet cherry varieties (Prunus avium L.). Three varieties —‘Rita’, ‘Bigarreau Burlat’ and ‘Carmen’— were crossed with ‘Early Star’ as male parent. Germination rate was affected by the developmental stage of both fruit and embryo. Fruit ripening stage was a critical factor for culture infection rate that increased with maturity. In-ovule embryo culture on Murashige and Skoog medium without hormones improved the embryo size but did not increase the germination rate due to a further increase in infection rate. Ex-ovule embryo culture on Murashige and Skoog medium supplemented with BA 1 mg L^?1, NAA 0.5 mg L^?1, 20 g L^?1sucrose, 10 g L^?1 sorbitol and 6 g L^?1agar during the stratification time increased embryo length. Germination was performed on Brooks and Hough medium at the 22?±?1?°C with 16/8 h light/dark photoperiod. The highest germination rate (75?%) was reached in embryos that were 3?4 mm in length, after 30-days stratification at 4?°C. Embryos in fruits at green-yellow stage that were 3?4 mm long were morpho-physiologically developed to produce bipolar seedlings, without combined application of embryo culture and micropropagation.     

Production of four commercially cultivated Echinacea species by different methods of in vitro regeneration

Summary

Efficient in vitro procedures for mass propagation of four commercially important Echinacea species have been deveoped. Plants of E. angustifolia, E. pallida, E. paradoxa and E. purpurea were regenerated by three methods, namely axillary bud proliferation, adventitious shoot formation and somatic embyrogenesis. Shoot tips obtained from in vitro germinated seedlings, adventitious shoots or somatic embryo-derived plantlets, when cultured on Murashige and Skoog medium enriched with 1 μM 6-benzylaminopurine, 2 μM kinetin, 0.5 μM indole-3-butyric acid and 4 mg^–1 paclobutrazol multiplied three-fold within 3–4 weeks in culture. Incorporation of paclobutrazol in the shoot multiplication medium was necessary to recover healthy and robust shoots suitable for rooting. Direct, high-frequency shoot formation on intact leaves of shoots grown on 6-benzylaminopurine and kinetin-supplemented media, an unusual and novel observation made in this study, occurred in all the species studied. Rooting of in vitro developed shoots was achieved relatively easily with Murashige and Skoog basal medium rather than with auxin-enriched media. Culturing of hypocotyl explants on medium containing 3,6-dichloro-o-anisic acid (commonly known as dicamba), or 2,4-dichlorophenoxyacetic acid, resulted in direct somatic embryogenesis in all the species examined. The presence of cytokinin was required for somatic embryo germination, but further development of germinated somatic embryos into normal plantlets occurred in Murashige and Skoog medium. We conclude that the procedures described here could be used for rapid propagation as well as genetic transformation of commerically cultivated Echinacea species.     

夏蜡梅与美国蜡梅属间杂交障碍的组织学机理

 以夏蜡梅属夏蜡梅（Sinocalycanthus chinensis）和美国蜡梅属美国蜡梅变种光叶红蜡梅（Calycanthus floridus var. oblongifolius）为试验材料进行属间杂交,通过荧光镜检观察花粉在柱头上的附着和萌发以及利用石蜡切片观察杂种胚发育情况,探讨其杂交障碍机制。结果表明：不论正反交,花粉均能在柱头上粘附36 h到达胚囊,表明花粉萌发和花粉管生长阶段不存在杂交障碍。杂种胚发育观察结果表明,无论正反交均可以实现双受精,但结实率极低,说明属间杂交存在受精后障碍,且正反交杂交障碍机制有所不同：当以夏蜡梅为母本时,杂交障碍主要由受精后杂种胚早期的不正常解体造成;而当以光叶红蜡梅为母本时,杂交障碍主要由母本雌蕊较高比例的发育异常和杂种胚的早期败育共同引起。 、萌发并生长到达胚囊;以夏蜡梅为母本时父本花粉管生长进程较以光叶红蜡梅为母本时更加一致,大部分花粉管在授粉后     

Optimized scarification protocols improve germination of diverse Rubus germplasm

Seed collections of the wild relatives of cultivated blackberry and raspberry (Rubus species) are maintained at the National Clonal Germplasm Repository, Corvallis, OR. Information on wild species germination requirements is rarely available, and germination may be poor or slow, making it difficult for scientists to use them for breeding improved cultivars. Eight diverse Rubus species in 6 of the 12 Rubus subgenera from seed stored at −20 °C for 1–23 years were studied. Seed weight, seed-coat thickness and hardness varied widely. Scarification with sulfuric acid (98% H₂SO₄) or sodium hypochlorite (14% NaOCl) was followed by germination treatments of deionized water (DI), smoke gas or a combination of gibberellic acid (2.03 mg/L GA₃) and potassium nitrate (34 mg/L KNO₃) during stratification. The commonly used scarification protocols were not effective for many species; but effective scarification exposure was established based on the amount of embryo damage seen with 2,3,5 triphenyl tetrazolium chloride (TZ) viability testing. H₂SO₄ scarification followed by a treatment with KNO₃ and GA₃ during stratification was highly effective for the most species. Two species in subgenus Anoplobatus had a hilar-end hole that allowed rapid germination of unscarified seed. Some species with extremely hard seed coats had little or no germination, and longer scarification times are suggested based on seed size, seed-coat thickness and hardness and viability testing.     

Somatic embryogenesis and plantlet regeneration from encapsulated embryos of Selinum tenuifolium

Summary

This paper reports, for the first time, somatic embryogenesis and synthetic seed production in Selinum tenuifolium Wall. Mature leaf explants inoculated in Murishige and Skoog (MS) medium supplemented with 3 µM 2,4-dichlorophenoxyacetic acid (2,4-D), containing 3% (w/v) sucrose and 0.7% (w/v) agar, induced 67% callus. Maximum production of globular structures, their differentiation into embryos and germination, occurred with a combination of 2 µM benzyladenine (BA) and 2 µM indole-3-butyric acid (IBA). To protect somatic embryos and produce synthetic seeds, gel capsules were standardised using a combination of sodium alginate and calcium nitrate concentrations. Gel capsules were most effective when formed with a combination of 3% (w/v) sodium alginate and 100 mM calcium nitrate for 30 min. The addition of MS medium to alginate capsules with 3% (w/v) sodium alginate, 3% (w/v) sucrose, 2 µM BA and 2 µM IBA significantly improved their germination rate to 77.8%, as well as their resulting shoot length (5.6 cm) and root length (7.2 cm), compared to controls (57.8%). Most plantlets (66%) survived under nursery condition. Storage at 4°C for different periods (10 d or 20 d) significantly (P < 0.05) reduced the percentage survival and germination of somatic embryos and artificial seeds compared to controls or 5 d storage.     

In vitro development and germination of immature olive embryos

Summary

In vitro culture methods were used to germinate olive embryos prior to maturation. Fruit, seed and embryo development were established with consecutive sampling from 20 to 100 days after bloom. For that same period, embryo development and germination success were determined by in vitro culture trials using one-third strength MS medium with or without the addition of zeatin. For early developmental stages, when isolation of the embryo was difficult, a cut portion of the seed containing the embryo was used for culture. The embryos cultured within the cut seed portions germinated and formed normal plantlets. Histological observations indicated a close similarity between the natural and in vitro immature embryo differentiation pattern, progressing through preglobular, globular, heart-shaped and torpedo-shaped stages. In some cases, however, the in vitro immature embryos developed or germinated abnormally. The presence of zeatin (0.25 mg l^–1) in the culture medium and the use of a cut seed-portion containing the immature embryo allowed in vitro germination sooner after bloom than previously obtained. On the contrary, zeatin was a handicap for mature olive embryo in vitro germination, which reached 100% seedling formation when no plant growth regulators were used.     

Seed dormancy and germination of Michelia yunnanensis (Magnoliaceae)

Michelia yunnanensis Franch. is a Chinese endemic ornamental shrub with potential for greater utilization as a landscape and medicinal plant if propagation was less difficult. Seed development and breaking of seed dormancy were investigated to improve propagation of M. yunnanensis. No fresh seeds germinated when tested at the time of dispersal. Newly matured seeds of M. yunnanensis contained differentiated linear underdeveloped embryos that were physiologically dormant. The embryo/seed length ratio of M. yunnanensis was 0.15. Warm stratification did not break seed dormancy. Dormancy was broken by cold stratification at 4 °C but not by flowing water or nitrate. Embryos developed grew inside seeds during cold stratification at 4 °C. In newly harvested dormant seeds, embryos were 0.94 mm long and increased in length 139% before radicle emergence (germination). GA₃ substituted for cold stratification to break dormancy in seeds of M. yunnanensis incubated at 25 °C or 20/25 °C. Mature M. yunnanensis seeds exhibited intermediate complex morphophysiological dormancy. Optimal germination of non-dormant seed in terms of both germination percentage and rate occurred at 20/25 °C.     

Dormancy and germination in Rosa multibracteata Hemsl. & E. H. Wilson

Most of the achenes produced by Rosa multibracteata Hemsl. & E. H Wilson are dormant on maturity and require pretreatment to stimulate germination. To investigate the mechanism of dormancy and to develop effective methods of improving germination, roles of the pericarp, testa, and embryo of R. multibracteata in regulating dormancy were studied by investigating the effect of different pretreatments on germination. The effects of temperature and water stress were also tested with achenes treated by warm plus cold stratification. In freshly harvested achenes, pericarps are permeable and the embryo fully developed, which eliminates the possibility of physical, morphological, or morphophysiological dormancy. Germination percentage remained low (<5%) despite softening the pericarp or even removing it fully. However, fully removing the testa improved germination significantly (39%), indicating the possible presence of germination inhibitors in the testa. Dry storage, scarification with sulphuric acid (H₂SO₄), and warm stratification proved ineffective by themselves but when combined with cold stratification, improved germination and shortened the cold stratification period needed to break dormancy. Dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks resulted in maximum germination (72–79%) among all the treatments. In achenes scarified with H₂SO₄, germination increased with an increase in the duration of cold stratification. Neither gibberellic acid (GA₃) nor ‘smoke water’ (water through which smoke had been bubbled for 2 h) had any positive effect on germination even on seeds that had been mechanically scarified or stratified. Both high temperature and water stress lowered germination in achenes treated with warm plus cold stratification. Our results suggest that R. multibracteata achenes have an intermediate physiological dormancy, and that dry storage for 68 weeks followed by cold stratification for 16 or 24 weeks is the best method for propagating R. multibracteata from seed.     

The Effect of Scion on Root.: II. Stem-Worked Apples.

Summary

The effects of seed coat removal and chilling on the germination of seeds of ten cultivars of ornamental peach (Prunus persica Batsch) were investigated. Seeds were rinsed in running tap water for 48 h in order to facilitate seed coat removal. Only a few non-chilled, intact seeds germinated (e.g., 6% of ‘Hito’ seeds). Seed coat removal and no chilling resulted in some seed germination in eight of the ten cultivars, ranging from 6% to 83%. Chilling intact seeds at 5°C for up to 10 weeks resulted in greater frequencies of germination (average = 85% germination) than seed coat removal before (average = 80%) or after chilling (average = 73%). There was a linear decrease in the germination percentage with an increase in abscisic acid (ABA) content for ‘Yaguchi’,‘Kanpaku’, and ‘Kikumomo’ seeds (R = –0.66; P <0.001). The most consistent decrease in total seed ABA content (average of 64%) occurred during the 48 h rinsing period. In ‘Kanpaku’, dry seeds had an intermediate ABA content (13 ng per seed); but, in the embryonic axes, this increased from 0.03 ng to 1.2 ng per seed with an increase in the duration of the chilling period. The lowest germination percentages were found in this cultivar. These results suggest that ABA synthesis in the embryonic axes during chilling may affect the varietal characteristic of seed dormancy, and that rinsing seeds for >48 h could remove sufficient ABA to allow seed germination with minimum chilling.     

Environment and its Influence Upon Deciduous Fruit Production

Summary

Turkey has a huge wild Pistacia germplasm that mainly includes P. terebinthus, P. atlantica and P. eurycarpa species. In this study, seed and seedling behaviour of these species are characterized at intra- and inter-specific level. Seed and seedlings of 63 Pistacia genotypes: 10 P. terebinthus, 45 P. atlantica and eight P. eurycarpa genotypes from different parts of Turkey were evaluated as their characteristics of germination, seedling growth and budding success. Correlations between morphological traits of maternal trees and seed/seedling characteristics of their progeny were performed as well. There was a large variability for each of the evaluated character at the inter- and intra-specific level. However, in the average, P. eurycarpa had the highest germination percentage, whereas P. terebinthus had the lowest. The seedling growth of P. atlantica was better than P. terebinthus and P. eurycarpa. Budding success was not significant between species. Correlation coefficient values suggested that a few of the associations between morphological traits of maternal trees and seed germination and seedling characters of their progeny vary between those of three species.     

Effects of temperature and seed coat treatments on germination of sweet pea

Tests on seeds of sweet pea (Lathyrus odoratus L.) were set up to examine responses to temperature during germination and to investigate the effects of mechanical and chemical treatments on the permeability of the seed coat to water.Optimum temperatures for germination occurred at about 21 °C, and higher temperatures resulted in the production of fewer seedlings. Although temperatures below c. 15 °C also reduced the numbers of seeds which germinated, even at 2 °C more than 50 % germinated within 60 days.Treatments with concentrated sulphuric acid or the mechanical removal of part of the seed coat by filing greatly increased permeability to water and under some conditions improved germination responses. Filing, followed by exposure to excess free water, reduced germination rates, possibly as a result of loss of solutes from the seed during imbibition.     

The effect of seed treatment on the germination and early growth of Euterpe edulis (family Palmae)

The germination rate of palm seeds can be improved by pre-treatment of the seed. Several methods proved effective for Euterpe edulis seed, but sulphuric acid immersion and hydrogen peroxide leaching treatments both decreased emergence of germinated seedlings and restricted plant growth up to 6 months after germination.The best overall results in germination and subsequent seedling development were from seed leached in water for 72 hours at 30°C. This treatment can be related to the natural conditions encountered by the seed in the highly leached soils of a tropical rain forest.     

Histological and protein changes during early stages of seed germination in the orchid,Dendrobium crumenatum

Summary

During germination of seed of the tropical epiphytic orchid, Dendrobium crumenatum, cell division at the chalazal end of the globular embryo occurred after one week of culture on Vacin and Went medium. The larger cells at the middle and basal regions of the embryo continued to enlarge with distinct nuclei and chromatin, indicative possibly of endoduplication. Shoot apex organization at the chalazal end occurred after four weeks of culture. Mobilization of stored reserves was seen as a reduction in the granular nature of the cytoplasm after two weeks in culture. Utilization of protein reserves occurred within 6 d of germination. Subsequently, do novo synthesis and accumulation of cvs proteins increased steadily and reached an equilibrium between 18 and 24 d. Changes in profiles of specific proteins indicated development-specific protein accumulation. Two proteins of Mr 14 and 33 kDa were highly abundant in dry seeds but were degraded within 6 d of germination indicating their possible nutritive role in embryo development. Several other proteins showed steady increases during 24 d from germination.     

Improved seed development and germination of stenospermic grapes by plant growth regulators

Plant growth regulators were applied to the foliage and immature fruit clusters of the stenospermic grape selection ‘C35-33’ at various periods before bloom to stimulate viable seed development. In the 1987 season five different plant growth regulators were used, but in 1988 the growth retardants Cycocel and XE-1019 were used exclusively. Chemical treatments applied 35 days after bud break increased significantly germination percentage. Experimental results indicate that the use of certain plant growth regulators may aid in increasing the efficiency of seedless grape breeding by providing an alternative to in-ovulo embryo culture.     

Interspecific hybridization between three closely related ornamental Eucalyptus species: E. macrocarpa,E. youngiana and E. pyriformis

Summary

Interspecific hybridization between thre Eucalyptus species with horticultural merit, E. macrocarpa, E. pyriformis and E. youngiana, was undertaken to investigate the likelihood of success of such crosses. All combinations produced fertile seed, with interspecific crosses as successful as intraspecific. There were no differences between male species in fertility but there were differences between female trees within a species. Discriminant analysis of each cross indicated a high degree of interspecific hybridization for hybrid 166 seedlings, with all except two seedlings clustering separately from a mixture of selfed and outcrossed seedlings of either parent, when measured for a range of leaf and stem characters at three different nodes. The success of this programme in producing both large numbers of seed and large numbers of hybrids indicated that it is possible that these species could hybridize naturally if they were growing in the same location. It also demonstrated the potential of controlled pollination, between closely related species of similar floral morphology, and seedling-based hybrid recognition as a method to produce eucalypt hybrids for further evaluation for commercial horticulture.