Interspecific hybridization between Cicer arietinum and C. pinnatifidum

An interspecific hybrid between Cicer arietinum cv. GL 769 and a wild species C. pinnatifidum was obtained after emasculation, pollination and application of growth regulators. Ovules were cultured and embryos were later dissected to obtain hybrid plants. These plants were albinos and morphologically resembled C. pinnatifidum. Shrivelled seeds were also obtained in 2% of the crosses, which on germination gave rise to albino plants. These plants did not survive beyond 20 days. The hybrid nature of these plants was confirmed by esterase isozyme studies. Hybrid shoots obtained from germinating embryos were cultured on modified ML-6 medium with BAP 2 mg/1, IAA 0.5 mg/1, where they turned green after 3–4 weeks. Transmission electron microscopy (TEM) studies on leaf sections from green hybrid shoots showed an improvement in the chloroplast structure, with better organized grana.     

Factors affecting in vitro flowering and fruiting of green pea (Pisum sativum L.)

Multiple shoots were efficiently regenerated from cotyledonary node and shoot tip explants of Pisum sativum within 15 days on MS medium containing B₅ vitamins and supplelmented with 2.0 mgl^-1 6-benzylaminopurine. The elongated shoots produced on the same medium were excised and transferred to MS medium containing half strength ammonium nitrate (8.25 gml^-1) and supplemented with auxins (indole-3-butyric acid or naphthalene acetic acid) either alone or in combinations with gibberellic acid. Rooting and flowering were observed on the 7th and 15th day after their transfer to rooting medium. The flowers self-fertilised in vitro and produced mature pods within 25 days of rooting. These seeds were germinable both in vitro and in vivo. In vitro seeds sown in pots under field conditions developed into flowering plants, and subsequently produced pods with viable seeds. This revised version was published online in July 2006 with corrections to the Cover Date.     

Morphogenic response of the alginate encapsulated nodal segment and antioxidative enzymes analysis during acclimatization of Ocimum basilicum L.

Synthetic seed technology is a potential tool for a more efficient and cost effective rapid clonal propagation system. In the present investigation, synthetic seeds were produced by encapsulating nodal segments of Ocimum basilicum in calcium alginate gel. For encapsulation of nodal segment, 3% (w/v) sodium alginate and 75 mM CaCl₂.2H₂O were found most suitable. The synthetic seeds when cultured on half-strength Murashige and Skoog (MS) medium supplemented with 5.0 μM benzyladenine (BA) and 0.5 μM Indole -3- acetic acid (IAA) produced maximum number of shoots (7.9 ± 0.54) after 8 weeks of culture exhibiting 80% in vitro conversion response. Further, synthetic seeds stored at 4 °C for 4 weeks resulted in maximum conversion response (90%) when placed back to regeneration medium. Both root and shoot formation took place in the same medium but the roots were thin and difficult to handle. Individual elongated shoots were rooted on MS medium supplemented with 1.0 μM Indole -3- butyric acid (IBA). Plants regenerated from the synseeds were hardened, acclimatized, and established in soil with 80% survival rate. Changes in antioxidative enzymes viz., Superoxide dismutase (SOD) and Catalase (CAT) in O. basilicum indicated the adaptation of micropropagated plants to ex vitro conditions.     

Untersuchungen zum Einfluß der Bestandesdichte auf das Ertragspotential von Rapspflanzen (Brassica napus L. var. napus)*)

Investigations on the effect of number of plants/area on the yield potential of rapeseed plants (Brassica napus L. var. napus) Based on field experiments with winter rapeseed, the effect of number of plants per area on yield potential and components of yield were investigated. The dependence of yield from number of plants per area before and after winter was analyzed by manipulating the number of plants immediately after sowing and in spring before beginning of growth. The number of plants per area was varied between 10 plants/m² till 185 plants/m². The results show that the yield potential is partly dependend on the growing conditions before winter as influenced by the number of plants per area; the yield potential declines with increasing number of plants/area before winter; affected are the number of siliquae producing lateral shoots, the number of siliquae per shoot and seeds per siliqua. The growing conditions before winter, in this way control the capacity of the rapeseed plant to utilize environmental factors in the main growing period. 50–100 plants/m² before winter and 45–90 plants/m² after winter are within the compensation capacity of rapeseed plants.     

Salt-tolerance in Brassica juncea L. I. In vitro selection,agronomic evaluation and genetic stability

Summary In vitro selection of salt tolerant plants of Brassica juncea L. (Indian mustard) cv. Prakash has been accomplished by screening highly morphogenic cotyledon explant cultures on high NaCl media. Out of a total of 2,620 cotyledons cultured on high salt medium, 3 survived, showed sustained growth and regenerated shoots. They were multiplied by axillary bud culture on NaCl free medium. The salt-selected shoots retained salt tolerance following 3 month of growth and multiplication on control medium. While two of these somaclones flowered and set seeds, third one grew slowly, had abnormal leaf morphology and was sterile. The seed of the two fertile plants were sown in the field to raise R₁ segregating generation. Data were recorded for field, other agronomic components and oil content. The somaclonal lines, both selected salt-tolerant and non-selected, showed tremendous amount of variation for all the characters studied. One of the two tolerant somaclones invariably showed reduced height, longer reproductive phase and higher 1000 seed weight. Based on the agronomic performance of R₁ plants of these somaclones, some plants were selected and their progeny were evaluated for agronomic performance under standard field conditions and salt-tolerance in the greenhouse using sand pot culture method. Most of the lines bred true for their specific characteristics. In the greenhouse, selected salt-tolerant somaclones (SR-2 and SR-3) performed better for plant growth, yield and other agronomic traits at higher salt treatments, indicating thereby that salt-tolerance trait selected in vitro was expressed in the whole plants and is genetically stable and transmitted onto the progeny. The two tolerant lines, however, differed in their salt-tolerance during vegetative and reproductive phases as indicated by their salt-tolerance and stress susceptibility indices. The mechanism of salt-tolerance is not clear and needs to be further investigated.     

Grafting in vitro Regenerated Pea (Pisum sativum L.) Shoots as a Method for Obtaining Mature Plants

A method of grafting pea plants is proposed to allow rapid availability of a large number of mature plants from in vitro regenerated shoots. Plant regeneration was obtained from macerated vegetative apices and immature embryos, but regenerated shoots rooted with low frequency (ca. 10 %). When those shoots were grafted onto seedling stocks of the same cultivar, 80 to 85 % of the grafts survived, grew to maturity and produced seed.     

顶端调控措施对烤烟生长、内源激素及氮钾累积的影响

【研究目的】该文探讨了打顶初期2周内打顶和植物生长调节剂对烤烟生长、内源激素和氮钾累积的影响。【方法】在盆栽基质培养条件下,进行了打顶和打顶+生长调节剂处理,采用酶联吸附免疫测定技术分析了烤烟根和叶中内源IAA、ABA、GA3和ZR的变化。【结果】与不打顶相比,打顶能够降低烤烟叶内IAA、ABA、GA₃和ZR的含量,刺激根中IAA、ABA、GA₃和ZR的增加,其中1h时打顶叶中IAA含量比不打顶降低了2倍,14d时打顶根中IAA含量比不打顶和打顶生长调节剂处理增加了140.70%和110.77%,5h和24h时打顶根中GA₃含量比不打顶增加124.18%和106.66%。打顶和打顶＋生长调节剂处理干物质和氮素累积与不打顶相比主要在中上部叶、茎和根,钾累积量在叶和根中,茎和整株钾累积量降低。【结论】顶端的存在影响内源激素、光合作用产物和养分在烟株体内的累积,打顶后涂抹植物生长调节剂在一定程度上代替烟株顶端的作用。     

Maternal and embryonal control of seed colour by different Brassica alboglabra chromosomes

Most oilseed rape, Brassica napus, cultivars are black‐seeded. The progenitor species, Brassica rapa, has either yellow or black seeds, while known cultivars of the other progenitor species Brassica oleracea/alboglabra have black seeds. To determine which chromosomes of B. alboglabra are carriers of seed colour genes, B. rapaalboglabra monosomic addition lines were produced from a B. napus resynthesized from yellow‐seeded B. rapa and brown/black‐seeded B. alboglabra. Eight out of nine possible lines have been developed and transmission frequencies of the alien chromosomes were estimated. Three B. alboglabra chromosomes in three of these lines influenced seed colour. B. rapa plants carrying alien chromosome 1 exhibited a maternal control of seed colour and produced only brown seeds, which gave rise to plants with either yellow or brown seeds. However, B. rapa plants carrying alien chromosome 4 or another as yet unidentified alien chromosome exhibited an embryonal control of seed colour and produced a mixture of yellow and brown seeds. The yellow seeds gave rise to yellow‐seeded plants, while the brown seeds gave rise to plants that yielded a mixture of yellow and brown seeds, depending on the absence or presence, respectively, of the B. alboglabra chromosome. Consequently, both maternal and embryonal control of seed colour are expected to contribute to the black‐seeded phenotype of oilseed rape.     

Micropropagation of intra and interspecific Lens hybrids

An intraspecific (Tetir × ILL 323) and an interspecific (Alpo × L. odemensis) lentil hybrid were multiplied in vitro in three consecutive micropropagation cycles to increase the production of F₂ seeds. Cloning efficiencies were slightly higher for Tetir × ILL323 (83%) compared to Alpo × L. odemensis (67%). A total of 982 F₂ seeds were produced in the experiment with Alpo × L. odemensis, consisting of the 334 F₂ seeds of the original hybrid and 648 F₂ seeds produced by the 12 plants cloned; consequently, F₂ seed production was increased three-fold over the original hybrid (194%). A total of 6050 F₂ seeds were produced in the experiment with Tetir × ILL 323, made up of the 483 F₂ seeds of the original hybrid and 5567 F₂ seeds produced by the 15 plants cloned; therefore, F₂ seed production was increased by more than twelve-fold over the original hybrid (1153%). In both hybrids the F₂ seed production of cloned plants diminished in the three consecutive multiplication cycles, with the plants having experienced less vegetative development. In lentil, F₂ seed production of cloned plants is related for the first time to the length of their period of vegetative development. In conclusion, micropropagation of hybrids is an interesting tool to construct from a single individual large F₁ populations that enable to increase by a manifold the production of F₂ seeds useful for genetic studies and breeding.     

Isolation of triploid and tetraploid olive (Olea europaea L.) plants from mixoploid cv. 'Frantoio' and 'Leccino' mutants by in vivo and in vitro selection

This paper reports a procedure for isolating triploid and tetraploid olive plants, which have not been produced before either artificially or in nature. These polyploids were isolated from two mixoploid somatic mutants obtained earlier by treating Trantoio' and ‘Leccino’ plantlets with gamma radiation. The mixoploid mutants exhibit increased thickness of leaf, stem and root tissues, short internodes, a modified leaf lamina shape and a strong resistance to Spilocaea oleagina (Cast.) Hugh. In addition, they produce a mixture of normal drupes and some abnormally large ones, almost twice normal size. The variation in the nuclear DNA content of the mixoploid mutants is closely correlated with variation in their pollen size, crop capacity and the production of large fruit. Triploid genotypes with 69 chromosomes were isolated by germinating the seeds of these large fruits, collected from both the mixoploid mutants. Tetraploid plantlets, with 92 chromosomes, were obtained from cv. ‘Frantoio’ by selecting in vitro, during several proliferation phases, the shoots with obvate leaf shape which occurred among the shoots with normal lanceolate or intermediate leaf shape.     

抗除草剂基因在黄瓜杂种纯度快速鉴定上的应用研究

黄瓜抗除草剂转基因T0植株经除草剂抗性筛选,连续2代自交获得T1和T2种子;分别对T1植株进行bar基因PCR检测和T2植株Southern杂交检测,证明bar基因已整合到黄瓜染色体上;以非转基因黄瓜为对照,摸索出田间抗性鉴定和室内种子抗性鉴定的除草剂临界浓度;从田间和室内筛选除草剂抗性纯合性转基因株系3个;以表现较好的2个抗性纯合转基因株系为父本,与非转基因母本杂交,获得F1种子,并在室内进行了杂交种纯度鉴定,鉴定效率达100％。建立了一套在种子发芽阶段或2片真叶期进行黄瓜杂交种纯度鉴定的新技术。     

Interspecific hybridization inBrassica juncea × Brassica hirta using embryo rescue

Summary Interspecific hybrids have been obtained in an otherwise incompatible cross betweenBrassica juncea × Brassica hirta through the in vitro culture of hybrid ovules and ovaries. The best response was observed from ovules and ovaries cultured 10–15 and 5–7 days after pollination respectively on a basal medium supplemented with indoleacetic acid, kinetin and casein hydrolysate. In some cases the basal cut end of the ovaries proliferated to form callus and shoots. The in vitro-derived hybrid seeds varied in their colour, size and shape, and the F₁ plants in the field showed a large diversity in their morphological traits. The hybrids were sterile, and had an intermediate number of chromosomes (2n=30).     

打顶对棉花赘芽生长的影响及其激素调控

以赘芽生长势强的冀151和269系及赘芽生长势弱的冀棉169和182系作为材料,观察打顶(D)、打顶+顶施IAA(D+T)和打顶+果枝顶芽施用IAA(D+F)处理下赘芽的生长势以及内源Z+ZR与IAA含量的变化。结果显示,棉花上部赘芽在打顶20 d后显著伸长,内源Z+ZR水平在打顶6 h后也明显提高,IAA水平显著下降;而D+T和D+F处理的棉花上部赘芽的伸长及内源Z+ZR水平的提高幅度均明显低于D处理,IAA含量则无显著变化。表明棉花茎节处合成的CTK促进赘芽生长,其水平受茎中由上而下IAA流的控制。棉花赘芽的生长既受主茎中IAA流调控,也受果枝中IAA流的影响。     

Sexual transfer of Arabidopsis DNA to Brassica napus

Out of 400 reciprocal crosses made between Brassica napus and Arabidopsis thaliana, 200 maternal B. napus flowers produced 31 seeds and 10 seeds developed when A. thaliana was used as the female parent. Of the latter, three seeds successfully germinated but did not develop into mature plants. In contrast, plants from all 32 seeds generated from B. napus were established. DNA from these 31 plants was analysed by 18 probes mapped to the A. thaliana genome, two selectable marker genes and one A. thaliana species-specific repetitive probe. It was found that one plant had identical restriction fragments to A. thaliana with two of the 21 probes used. The gene flow within Brassicaceae is discussed in light of this result.     

An assessment of morphogenic and transformation efficiency in a range of varieties of potato (Solanum tuberosum L.)

Summary To provide a truly genotype-independent transformation system, it is necessary to be able to transform a wide range of potato genotypes. The ability to regenerate shoots in vitro was determined for 34 potato varieties using tuber disc explants. Following a culture regime used extensively in previous studies with the variety Desiree, half of the varieties could be regenerated from tuber discs and half could not. From a sample of varieties that could be regenerated from tuber discs, all but one variety gave transgenic plants. Twelve varieties were evaluated for the capacity to regenerate shoots from leaf and internode explants excised from in vitro grown plants. All of the varieties tested regenerated adventitious shoots. Leaf and internode explants from 5 varieties were subsequently used for transformation, and transgenic plants were produced from two potato varieties that did not give transgenic plants from tuber disc explants. Some varieties could not be transformed by either method, and will require modification of the in vitro regeneration and transformation system to be successful.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid     

Role of the maternal effect phenomena in improving water stress tolerance in narrow‐leafed lupine (Lupinus angustifolius)

This paper describes experiments concerning improvement of drought tolerance in narrow‐leafed lupine (Lupinus angustifolius L.) by maternal effects. The first step involved harvesting seeds from plants exposed and not exposed to drought during flowering and seed ripening. The next‐generation plants grown from these seeds were exposed to drought and the effects of this stress on their physiological processes were examined. To find out whether drought applied to parent plants may affect tolerance to this stress in progeny plants such features as plant growth, tissue water content, abscisic acid concentration and yield‐related parameters were assessed. The study revealed that the progeny plants grown from the seeds of drought‐treated plants were more tolerant to this stress than the plants grown from the seeds harvested from optimally watered maternal plants. Drought tolerance was manifested by a reduced concentration of abscisic acid, increased plant height and maintaining high leaf water content. Most importantly, these plants produced significantly higher yield when exposed to drought than the plants grown from the seeds harvested from optimally watered plants.     

The sulphur-rich Brazil nut 2S albumin is specifically formed in transgenic seeds of the grain legume Vicia narbonensis

Summary Epicotyl explants were co-cultivated with Agrobacterium tumefaciens EHA101 to transfer a chimeric 2S albumin gene construct carried in the binary Ti plasmid vectors pGSGLUC1 or pGA472 into the grain legume Vicia narbonensis. This gene encoding the sulphur-rich Brazil nut albumin was under the control of either the CaMV 35S promoter which permits gene expression in all organs, or the Vicia faba legumin B4 promoter which elicits seed-specific gene expression. After callus formation and selection for kanamycin resistance, somatic embryos were induced which, in the case of transformation with the vector pGSGLUC1, were screened for GUS activity. Embryos that produced GUS were in addition analysed for 2S albumin formation. Selected transgenic embryos were cloned by multiple shoot regeneration. Rooted and fertile plants were obtained by grafting transgenic shoots on the appropriate seedlings. R₁ and R₂ generations were raised and analysed for GUS as well as 2S albumin gene expression.Expression of the 35S promoter/2S albumin gene fusion took place in all organs of the transgenic plants including the cotyledons of seeds, whereas seed-specific gene expression was found in transformants with the legumin promoter/2S albumin gene fusion. The 2S albumin accumulated in the 2S protein fraction of transgenic seeds and its primary translation product was processed into the 9 and 3 kDa polypeptide chains. The foreign protein was localised in the protein bodies of the grain legume. Analysis of the R₂ plants indicated Mendelian inheritance of the 2S albumin gene. In homozygous V. narbonensis plants the amounts of 2S albumin were twice that present in the corresponding heterozygous plants. Whereas only low level formation of the foreign protein was achieved if the gene was under the control of the 35S promoter, approximately 3.0% of the soluble seed protein was 2S albumin if seed-specific gene expression was directed by the legumin B4 promoter. Some of these transformants exhibited a three-fold increase in the methionine content of the salt-soluble protein fraction extracted from seeds.Abbreviations 35S cauliflower mosaic virus 35S protein gene - GUS -glucuronidase - NPTII neomycin phosphotransferase II - LeB4 Vicia faba legumin B4 gene - 2S albumin Brazil nut (Bertholletia excelsa) 2S albumin - ER endoplasmic reticulum - rER rough endoplasmic reticulum - HPLC high pressure liquid chromatography     

Changes in Hormonal Balance: A Possible Mechanism of Pre‐Sowing Chilling‐Induced Salt Tolerance in Spring Wheat

There is a lack of knowledge about factors contributing to the chilling‐induced alleviatory effects on growth of plants under salt stress. Thus, the primary objective of the study was to determine whether chilling‐induced changes in endogenous hormones, ionic partitioning within shoots and roots and/or gaseous exchange characteristics is involved in salt tolerance of two genetically diverses of wheat crops. For this purpose, the seeds of two spring wheat (Triticum aestivum) cultivars, MH‐97 (salt intolerant) and Inqlab‐91 (salt tolerant) were chilled at 3°C for 2 weeks. The chilled, hydroprimed and non‐primed (control) seeds of the two wheat cultivars were sown in both Petri dishes in a growth room and in the field after treatment with 15 dS m^?1 NaCl salinity. Chilling was very effective in increasing germination rate and subsequent growth when compared with hydropriming and control under salt stress. Results from field experiments clearly indicated the efficacy of chilling over hydropriming in improving shoot dry biomass and grain yield in either cultivar, particularly under salt stress. This increase in growth and yield was related to increased net photosynthetic rate, greater potential to uptake and accumulate the beneficial mineral elements (K⁺ and Ca²⁺) in the roots and reduced uptake and accumulation of toxic mineral element (Na⁺) in the shoots of both wheat cultivars when grown under salt stress. Salt‐stressed plants of both wheat cultivars raised from chilled seed had greater concentrations of indoleacetic acid, abscisic acid, salicylic acid and spermine when compared with hydropriming and control. Therefore, induction of salt tolerance by pre‐sowing chilling treatment in wheat could be attributed to its beneficial effects on ionic homeostasis and hormonal balance. The results presented are also helpful to understand the chilling‐induced cross adaptation of plants in natural environments. Moreover, efficacy of pre‐sowing chilling treatment over hydropriming suggested its commercial utilization as a low risk priming treatment for better wheat crop production under stressful environments.     

In vitro chromosome doubling of Miscanthus sinensis

The aim was to develop an efficient chromosome doubling method for Miscanthus sinensis to enable the production of triploids and so avoid seed dispersal to the environment. Antimitotic treatments with colchicine or oryzalin were tested in M. sinensis cl. MS‐88‐110 on: (1) in vitro shoots and plants established in soil; (2) during propagation of embryogenic callus; and (c) during the initial stages of callus induction. All systems produced chromosome‐doubled plants. A higher percentage of tetraploids was found after antimitotic treatment at the explant or callus level compared with treatment of in vitro shoots or plants established in soil. In general, oryzalin was more toxic to plant material than colchicine. A higher frequency of chimeras was found among plants with altered ploidy level when the target was formed shoot buds compared with adventitious shoot formation from callus. Antimitotic treatment of embryogenic callus from shoot apices also resulted in a high degree of albinism.