Micropropagation of guava (Psidium guajava L.)

Summary

Guava (Psidium guajava L.) is difficult to propagate using conventional asexual techniques, with most growers using seedling planting stock. However, these seedlings are highly variable. We therefore developed an in vitro technique to clonally propagate guava. Various concentrations of BAP (6-benzylaminopurine) and TDZ (thidiazuron) were used to regenerate and micropropagate plants. Two explant sources were compared: greenhouse grown plants (GHRP) and in vitro-harvested axillary buds (IVDS). GHRP with BAP at 2 mg l^–1 gave 3.7 shoots per single node cutting with an average length of 0.7 cm. Shoots 3.0 cm long were obtained with 0.5 mg l^–1 BAP, however only 2.1 shoots per explant were produced. For IVDS, the largest number of shoots (3.9 per explant) was obtained with BAP at 0.25 mg l–1 , with an average shoot length of 1.6 cm. Generally, lower concentrations of BAP gave fewer but longer shoots. The highest number of roots and longest roots per shoot (5.4 and 2.0 cm, respectively) were obtained with 1 mg l^–1 indole-3-butyric acid (IBA). A protocol for producing clonal plants over eight weeks is described.     

Micropropagation of fastigiate bird cherry (Prunus padus L.) and adventitious shoot formation from leaves

A shoot tip of a mature clone of fastigiate bird cherry (Prunus padus L.) was successfully established in vitro. Culture of shoot tip explants on a Murashige and Skoog (MS) based medium with phloroglucinol (PG) resulted in micropropagation, but the clonal line gradually became hyperhydric on this medium. This problem was overcome using PG- free medium based on either MS or Driver and Kuniyuki Walnut medium (DKW). Heavier cultures with more shoots were obtained on DKW medium with fructose or glucose rather than sucrose or sorbitol. Leaf explants placed on DKW basal medium with benzyladenine (BA) produced adventitious shoots. Addition of 1-naphthaleneacetic acid to media with BA increased regeneration. More leaves produced shoots on medium with sucrose or sorbitol rather than glucose or fructose. Adventitious shoots were excised and micropropagated. Shoots were rooted by insertion into DKW medium with indol-3yl- butyric acid, followed by transfer to hormone-free DKW. PG increased the proportion of shoots that produced adventitious roots.     

基于均匀设计法优化紫肉甘薯高效快繁体系

以紫肉甘薯嫩茎段为外植体,应用均匀设计法筛选最适合的培养基。结果表明,最适合嫩茎段腋芽萌发生长及生根的最佳培养基为：MS（改良）＋IAA0．10mg／L＋IBA0．30mg／L＋GA31．10mg／L,再生率达99．5％以上。以再生植株的茎节为材料进行快繁的结果表明,在21d的一个培养周期内增殖倍数平均达50以上。建立了紫肉甘薯的高效快繁体系。     

Micropropagation of the strawberry tree,Arbutus unedo L.

Actively growing shoots of potted greenhouse-grown strawberry tree (Arbutus unedo L.) were initially sterilised and established in basal woody plant medium containing 11.1 μM BA. Optimum shoot proliferation was achieved on a basal WPM containing MS vitamins, sucrose, agar and 22.2 μM BA. Microshoots rooted successfully in basal in vitro medium containing 10 μM IBA or IAA, but their survival rate during acclimatisation was low. Addition of a mixture 1 part peat:4 parts perlite in the basal in vitro rooting medium (1:1 v/v) containing 10 μM IAA resulted in high rooting percentage and plantlets with branched roots. These plantlets were successfully acclimatised. This novel rooting medium can be exploited further due to its potential in commercial applications.     

Quality of Highbush Blueberry (Vaccinium corymbosum L.) and Bilberry (Vaccinium myrtillus L.) Jam

ABSTRACT

Jam from wild bilberries and from the blueberry culti vars ‘Bluecrop’ and ‘Berkeley’ were analyzed by means of sensory profiling and by instrumental measurement of anthocyanins, color, pH and soluble solids. The study shows that bilberry jam has more “bluish black color,” compared to a more “reddish-blue color” and “glossy” surface of the jam from cultivated blueberries. Bilberry jam was less “smooth” and higher in “viscosity” and “berry density” as well as less distinct in “flavor of flowers and fruits,” while the “blueberry flavor and odor” were more distinct in the bilberry jam than that made of highbush blueberries. Analysis of color by means of sensory hue and instrumental a Hunter lab corresponded well, as did saturation measured by the sensory method and chroma instrumentally measured.     

Micropropagation and accumulation of essential oils in wild sage (Salvia fruticosa Mill.)

A protocol for in vitro propagation of the wild three-lobed sage (Salvia fruticosa Mill.) (Synonym, Salvia triloba L.) was developed. Shoot tips were excised from in vitro seedlings and established on MS, Nitch and Nitch (NN), or B5 medium. For shoot proliferation, in vitro nodal and apical explants were cultured on MS medium containing 0.25–2 μM 6-benzylaminopurine (BA), 6-furfurylaminopurine (kinetin), or thidiazuron (TDZ). Proliferated microshoots were rooted on MS medium supplemented with 2.7–11.4 μM indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or α-naphthaleneacetic acid (NAA). Results indicated that shoots established at 100% regardless of media type, however, shoot height, nodes per shoot, and leaf number were highest for explants established on MS medium compared to NN or B5. Number and height of proliferated shoots, nodes per shoot, and leaf number were highest for nodal explants cultured on a medium containing 0.75 μM BA. Microshoots cultured on a medium supplemented with 2.7 μM IBA exhibited the highest rooting percentage compared to those cultured with IAA or NAA. Essential oil composition in microshoots and shoots of greenhouse-grown plants was determined by gas chromatography/mass spectrometry. The major essential oils detected in both plant materials were α-pinene, 1,8-cineole, camphor, and borneol. No α-thujone or β-thujone was detected. The content of essential oils, camphor, and borneol were higher in the microshoots than in shoots of greenhouse-grown plants.     

Karambole (Averrhoa carambola L.)

The carambola (Averrhoa carambola L., family Oxalidaceae) is believed to have originated in Sri Lanka and the Moluccas but it has been cultivated in southeast Asia and Malaysia for many centuries. The evergreen tree is slow-growing, has a rounded crown and reaches 6 to 9 m in height. The 5- to 6-angled fruits (6 to 15 cm long and up to 9 cm wide) have thin, waxy, orange-yellow skin and juicy, yellow flesh. The fruit has a more or less pronounced oxalic acid odor and the flavor ranges from very sour to middle sweetish. The carambola is a tropical and subtropical tree, it can tolerate freezing temperature (?2°C) for short periods and sustain little damage. Trees can be propagated by seed, grafting, budding, and air layering. Tissue culture propagation has met only limited success. Plant spacing varies with growing region and cultural practices. Tree training is practiced intensively in different countries. Harvest timing and postharvest handling are critical to successful marketing of fresh fruit. Carambola is a nonclimateric fruit. Growers carefully harvest fruit by hand at color break — light green fruit with yellow color. The storage conditions should be 5 to 10°C and 85 to 95% relative humidity. Most carambola fruit is eaten fresh, used in salads, desserts, and cooked as star-shaped slices; fruit can also be dried, canned and frozen. The leaves have been eaten as a substitute for sorrel. Commercial production occurs in Taiwan, Malaysia, southern China, the Philippines, Australia, USA (Florida, Hawaii), Brazil, Suriname and Guyana. Production and consumption appears on the rise throughout the world and will most likely increase as selection and breeding for superior tasting cultivars with improved handling characteristics and storage conditions are found.     

The importance of male red mason bee (Osmia rufa L.) and male bufftailed bumblebee (Bombus terrestris L.) pollination in blackcurrant (Ribes nigrum L.)

Summary

Male wild bees visit flowers to feed and, despite their lack of specialised organs for carrying pollen, simultaneously pollinate them. We analysed the pollinating efficiency of the males of two bee species for blackcurrant (Ribes nigrum L.): red mason bee (Osmia rufa L.) and bufftailed bumblebee (Bombus terrestris terrestris L.). Both bee species are commercial pollinators and many males are produced during their rearing. Gauze sleeves were used to isolate the inflorescences and to keep the males inside (one per sleeve). In each experimental group, there were six shoots with four neighbouring inflorescences (n = 24). The sleeves were also used to prevent other bees from reaching the flowers, and to allow self-pollination. Non-isolated flowers were pollinated by free-range bees. The effect of male bee pollination was similar to that of free-range bee pollination. The percentages of flowers that developed into fruit were as follows: male bufftailed bumblebee pollination, 79.5%; free-range bee pollination, 71.1%; male red mason bee pollination, 65.1%; and self-pollination, 46.4%; while the mean numbers of fruit per raceme were 5.0, 4.4, 3.6, and 2.4, respectively. The number of non-pollinated flowers per raceme (ranging from 1.3 – 2.8) exhibited an inverse relationship to these numbers of fruit. Our observations showed that male wild bees can pollinate blackcurrant flowers successfully, and could potentially be useful in other crops.     

Competition of redroot pigweed (Amaranthus retroflexus L.) and nettle-leaved goosefoot (Chenopodium murale L.) with tomato (Lycopersicon esculentum Mill.) cultivars

Competition of 31 tomato (Lycopersicon esculentum Mill) cultivars with Amaranthus retroflexus and Chenopodium murale was investigated at different growing periods under natural conditions, University of Jordan, during 2008–2010. Cultivars were varied in their competitiveness with weeds; some tolerated while others were highly susceptible and exhibited great growth (shoot dry weight) and fruit yield reductions. A. retroflexus was more competitive than C. murale at most growing periods. Weeds attained high growth in the spring and summer but were much reduced in autumn. A. retroflexus requires relatively higher temperature for growth and competitiveness than C. murale. Gardners Delight and Special Back cultivars showed tolerance and their growth and yield either increased or least reduced in competition with weeds. In contrast, growth of First in the Field, Back More, Orient and Tiny Tim was reduced by 65–75% of their controls. Highest growth of weeds was in competition with The Amateur and lowest with First in the field and Back More. Fruit yield of all cultivars was reduced in competition, especially with A. retroflexus. Reduction was up to 100% in the spring. Both weeds reduced growth of cultivars most during the spring while A. reteroflexus eliminated certain cultivars.     

日本石楠工厂化快繁体系的建立及再生苗遗传稳定性的分子鉴定

 以日本石楠[Photinia glabra (Thunb.) Maxim.]为材料,建立了一套高效的适合工厂化生产的腋芽再生组织培养体系。该体系包括芽诱导培养基（MS＋1.2 mg·L^-1 BAP ＋ 0.2 mg·L^-1NAA）,继代培养基（WPM＋0.75 mg·L^-1BAP＋0.15 mg·L^-1NAA）和生根培养基（1/2MS＋2.5 mg·L^-1IAA＋0.3 mg·L^-1IBA）。在培养出的超过10万株的组培再生苗中,随机选出36株和24株进行AFLP和MSAP检测遗传和DNA甲基化的变化。在检出的615条AFLP条带和392条MSAP条带中,并未发现任何变异,表明建立的腋芽再生培养体系稳定可靠,适合于日本石楠的工厂化生产。     

Micropropagation of Capsicum frutescens L. using axillary shoot explants

A novel micropropagation protocol was established for Capsicum frutescens L. cv. ‘Uchithi’, a pungent chilli cultivar, through induction of axillary shoot proliferation of in vitro raised plantlets by decapitation and using the axillary shoots as explants for multiple shoot bud induction. About 2–6 axillary shoots were induced within 2 weeks when 4-week-old in vitro raised plantlets were decapitated. The axillary shoot-tip explants produced multiple shoot buds when cultured on Murashige and Skoog's (MS) medium containing 8.8–44.4 μM 6-benzylaminopurine (BAP) or 9.3–46.7 μM kinetin alone or 8.8–44.4 μM BAP with 4.6 μM kinetin or 5.7 and 28.5 μM indole-3-acetic acid (IAA). Maximum number of shoots (5.6) were induced on medium containing 22.2 μM BAP in combination with 4.65 μM kinetin. The separated shoots rooted and elongated on medium containing 2.8 μM IAA or 2.4–4.9 μM indole-3-butyric acid (IBA). Rooted plantlets were successfully established in the soil. Efficient mass multiplication of this important food crop was achieved.     

黄瓜(Cucumis sativusL.)花药培养

以卡罗尔、HH1-8-57与津绿农家乐3个不同基因型黄瓜品种为试材,在Kumar等、Song等和詹艳等试验研究基础上,设计试验分别探讨低温预处理时间、培养基成分(胚性愈伤组织诱导培养基、胚状体诱导培养基)和基因型等因素对黄瓜花药培养的影响。结果表明:在4℃低温预处理2d时,胚性愈伤组织诱导率显著高于其他处理;在MS+1.0mg·L-12,4-D+0.5mg·L-16-BA+3%蔗糖+0.8%琼脂培养基上胚性愈伤组织诱导率最高,达到81.3%;在MS+0.1mg·L-1NAA+3.0mg·L-16-BA+3%蔗糖+0.8%琼脂培养基上胚状体诱导率最高,为40.0%;基因型间胚性愈伤组织诱导率及胚状体诱导率差异显著,津绿农家乐品种胚性愈伤组织诱导率最高,达到81.1%,HH1-8-57胚状体诱导率最高,为40.0%。本研究从2份试材中成功地诱导出胚状体并获得了黄瓜单倍体再生植株。     

Aerial tubers induced in turnip (Brassica rapa L. var. rapa (L.) Hartm.) by gibberellin treatment

We investigated the tuberization ability of the turnip (Brassica rapa L. var. rapa (L.) Hartm.) epicotyl. Epicotyl elongation was forced by continuous gibberellin (GA₃) application to make the epicotyl distinguishable from the fleshy hypocotyl and root. Tubers were induced mainly on the stunted apical parts that formed after cessation of GA₃ application. All of the five cultivars tested included non-tuberized plants and plants with various degrees of tuberization. Tuberization was caused by secondary growth of the xylem. Many long rows of vessels were arranged radially on the cross-section of the tuber. These histological characteristics are the same as those of the fleshy hypocotyl and root. Tuberization was very likely a genetic trait, because tuberous and non-tuberous lines were clearly distinguishable in the S₂ generation. These results suggest that B. rapa has potential for tuberization ability similar to that of kohlrabi (Brassica oleracea L. var. gongylodes L.) and swollen-stem mustard (Brassica juncea (L.) Czern. et Coss. var. tumida Tsen et Lee).     

Standardization of Rootstocks of Mango (Mangifera Indica L.)

Mango cuttings could be induced to form roots provided IBA at 5,000 p.p.m. in lanolin was applied at the base of shoots after removing a ring of bark while they were still attached to the mother tree.

Cuttings taken from one-month-old seedlings gave the highest percentage of rooting and establishment, but with increasing age of the mother plants the rooting was considerably reduced. The rooting of cuttings of different age groups could be improved by using shoots forced into vigorous growth by hard pruning. Younger plants responded better to such treatment than older ones.

Cuttings from etiolated shoots rooted better than those from non-etiolated, but etiolation was less effective in promoting rooting than invigoration by hard pruning. Etiolation and invigoration combined gave the highest percentage of rooting and establishment in all age groups.     

Heterosis studies in chilli (Capsicum annuum L.)

By top-crossing 12 different homozygous chilli varieties with a genetic male sterile (MS), 12 hybrids were produced. Heterosis over mid-parent (MP) and superior parent (SP) was studied for days to flower, plant height, number of primary branches, length of fruit, number of fruits per plant and fruit yield per plant. Degree and direction of heterosis varied greatly for different characteristics and crosses studied. The hybrid MS × K-2 exhibited significant positive heterosis for fruit yield over its SP (157%), followed by MS × Pant-C-1, MS × Japanese bunch variety and MS × Bhiwapur local, indicating that male sterility can be utilised for commercial exploitation of hybrid vigour. Heterosis was observed for days to flower, plant height, number of primary branches, fruit length and number of fruits per plant.     

黄瓜耐热性研究进展

就近年来有关高温对黄瓜生长发育的影响、黄瓜耐热性的评价以及耐热性的遗传作了简要综述,对黄瓜耐热性研究存在的问题进行了总结,并展望了黄瓜耐热性研究的方向。     

In vitro grafting of cashew (Anacardium occidentale L.)

A successful micrografting technique in cashew was developed using in vitro germinated seedlings as rootstocks and axenic shoot cultures (shoot-tip and nodal cultures) established from mature tree source as microscions. In vitro germinated seedlings, which emerged 20–25 days after inoculation on absorbent cotton, were decapitated and used as rootstock. Mature tree explants initiated on hormone-free Murashige and Skoog [Physiol. Plant. 15 (1962) 473] (MS) modified medium were made into scion of 3–15 mm length for grafting. Micrografts could be easily cultured on hormone-free liquid half-MS medium and were potted out after 10–12 weeks of culture growth. Grafting success was dependent on the method of grafting and size of the scion. Shoot-tip grafting and side grafting were equally successful (79.5–100%). Length of scion shoot had significant effect on micrografting success. Graft success was high (79.5%) when the scion length was >5 mm and it was less (0.5%) when size of scion was small (3–5 mm). Scion presoaked in either water or 0.01% ascorbic acid and 0.015% citric acid (1:1) reduced phenolic browning and drying of scion. Micrografting techniques standardized could be used for rejuvenation of shoot explants of mature tree.     

黄瓜耐热性研究进展

就近年来有关高温对黄瓜生长发育的影响、黄瓜耐热性的评价以及耐热性的遗传作了简要综述,对黄瓜耐热性研究存在的问题进行了总结,并展望了黄瓜耐热性研究的方向.     

梨不同砧穗组合光合特性

 用CIRAS-1 便携式光合作用测定系统研究了豆梨(Pyrus betulaefolia Bunge) 、杜梨(P.calleryana Dcen.) 幼树以及豆梨、杜梨与砂梨(P. pyrifolia Nakai) 品种丰水、新高4 种砧穗组合幼树叶片的光合作用。结果表明, 砧木显著影响栽培品种的光合作用, 杜梨比豆梨以及以杜梨为砧木的丰水、新高幼树比以豆梨为砧木的两品种幼树叶片净光合速率(Pn) 、表观量子产量(Φi) 、羧化效率(CE) 、水分利用效率(WUE) 高。新高的Pn、Φi 、CE 和WUE 值较丰水高, 且在两种砧木上均表现出同样的结果。