茄子种质资源的耐冷性鉴定

采用低温胁迫下幼苗叶片冷害指数、种子活力指数、叶片电导百分率为指标,对34份不同类型的茄子种质资源进行耐冷性鉴定.结果表明,活力指数与冷害指数、电导百分率均呈极显著负相关,电导百分率与冷害指数呈极显著正相关.通过耐冷隶属函数值和聚类分析,初步筛选出11份耐冷性较强的材料.     

Abiotic stress tolerance in transgenic eggplant (Solanum melongena L.) by introduction of bacterial mannitol phosphodehydrogenase gene

In the present work, the bacterial mannitol-1-phosphodehydrogenase(mtlD) gene was introduced into eggplant(Solanummelongena L.) by Agrobacteriumtumefaciens-mediated transformation. Several transformants weregenerated and the transgene integration was confirmed by PCR, dot blot andSouthern blot analysis. Transgenic lines of T₀ and T₁generations were examined for tolerance to NaCl-induced salt stress,polyethylene glycol-mediated drought and chilling stress under bothinvitro and in vivo growth conditions. Aconsiderable proportions of transgenic seeds germinated and seedlings grew wellon 200 mM salt-amended MS basal medium, whereas seeds ofuntransformed control plants failed to germinate. Further, leaf explants fromthe transgenics could grow and showed signs of shoot regeneration onsalt-amended MS regeneration medium, whereas wild type did not respond, and infact the explants showed necrosis and loss of chlorophyll after about one week.The transgenic leaves could also withstand desiccation, and transgenics couldgrow well under chilling stress, and hydroponic conditions with salt stress ascompared to wild type plants. Thus, the transgenic lines were found to betolerant against osmotic stress induced by salt, drought and chilling stress.The morphology of the transgenic plants was normal as controls, but thechlorophyll content was higher in some of the lines. These observations suggestthat mtlD gene can impart abiotic stress tolerance ineggplant.     

Segregation distortion and linkage analysis in eggplant (Solanum melongena L.)

An anther-derived doubled haploid (DH) population and an F2 mapping population were developed from an intraspecific hybrid between the eggplant breeding lines 305E40 and 67/3. The former incorporates an introgressed segment from Solanum aethiopicum Gilo Group carrying the gene Rfo-sa1, which confers resistance to Fusarium oxysporum; the latter is a selection from an intraspecific cross involving two conventional eggplant varieties and lacks Rfo-sa1. Initially, 28 AFLP primer combinations (PCs) were applied to a sample of 93 F2 individuals and 93 DH individuals, from which 170 polymorphic AFLP fragments were identified. In the DH population, the segregation of 117 of these AFLPs as well as markers closely linked to Rfo-sa1 was substantially distorted, while in the F2 population, segregation distortion was restricted to just 10 markers, and thus the latter was chosen for map development. A set of 141 F2 individuals was genotyped with 73 AFLP PCs (generating 406 informative markers), 32 SSRs, 4 tomato RFLPs, and 3 CAPS markers linked to Rfo-sa1. This resulted in the assignment of 348 markers to 12 major linkage groups. The framework map covered 718.7?cM, comprising 238 markers (212 AFLPs, 22 SSRs, 1 RFLP, and the Rfo-sa1 CAPS). Marker order and inter-marker distances in this eggplant map were largely consistent with those reported in a recently published SSR-based map. From an eggplant breeding perspective, DH populations produced by anther culture appear to be subject to massive segregation distortion and thus may not be very efficient in capturing the full range of genetic variation present in the parental lines.     

Production of transgenic eggplant (Solanum melongena L.) resistant to Colorado Potato Beetle (Leptinotarsa decemlineata Say)

 A modified gene of Bacillus thuringiensis var. Tolworthi (Bt), encoding a coleopteran insect-specific CryIIIB toxin, was transferred via Agrobacterium tumefaciens to the female parent of the eggplant commercial F₁ hybrid ‘Rimina’. One-hundred and fifty eight transgenic plants were regenerated and tested by PCR and NPTII expression assays. The presence of the CryIIIB toxin in leaf extracts was demonstrated in 57 out of 93 transgenic plants tested by DAS-ELISA assay. High Bt-expressing plants contained a 74-kDa protein cross-reacting with serum anti-CryIIIB toxin. Twenty three out of 44 S. melongena plants tested by insect bioassay showed significant insecticidial activity on neonate larvae of Colorado Potato Beetle (CPB). The Bt transgene and the toxic effect on CPB larvae were transmitted to progenies derived by selfing. Thus, transgenic Bt eggplants represent a very effective means of CPB pest control. Received: 25 November 1996/Accepted: 31 January 1997     

Application of chlorophyll fluorescence to screen eggplant (Solanum melongena L.) cultivars for salt tolerance

The objective of this study was to investigate the relative salt tolerance of four eggplant cultivars (Solanum melongena L.) by studying chlorophyll (Chl) fluorescence parameters during the vegetative growth stage under increasing salinity levels. The plants were grown in pots filled with peat under controlled conditions and were subjected to the salt stress ranging from 0 (control), 20, 40, 80, and 160 mM NaCl for 25 days. The results showed that the increasing NaCl concentration affected hardly the maximum quantum yield of photosystem (PS) II. The quantum yield of PSII (Φ_PSII) decreased significantly in ‘Adriatica’ and ‘Black Beauty’ under the salt stress. The photochemical quenching decreased in ‘Black Beauty’ and nonphotochemical quenching increased in ‘Adriatica’ under the salt stress. The Chl fluorescence parameters did not change significantly under the salt stress in ‘Bonica’ and ‘Galine’, revealing their tolerance to salinity. After 25 days of the salt stress, the plant growth was reduced in all cultivars, however, this decline was more pronounced in ‘Adriatica’ and ‘Black Beauty’. Additionally, a significant correlation between the biomass and Φ_PSII was observed in ‘Adriatica’ and ‘Black Beauty’. Our results suggest that Φ_PSII can be used as a diagnostic tool to identify salt-tolerant egg-plant cultivars.     

Heterology expression of the Arabidopsis C-repeat/dehydration response element binding factor 1 gene confers elevated tolerance to chilling and oxidative stresses in transgenic tomato

In an attempt to improve stress tolerance of tomato (Lycopersicon esculentum) plants, an expression vector containing an Arabidopsis C-repeat/dehydration responsive element binding factor 1 (CBF1) cDNA driven by a cauliflower mosaic virus 35S promoter was transferred into tomato plants. Transgenic expression of CBF1 was proved by northern- and western-blot analyses. The degree of chilling tolerance of transgenic T(1) and T(2) plants was found to be significantly greater than that of wild-type tomato plants as measured by survival rate, chlorophyll fluorescence value, and radical elongation. The transgenic tomato plants exhibited patterns of growth retardation; however, they resumed normal growth after GA(3) (gibberellic acid) treatment. More importantly, GA(3)-treated transgenic plants still exhibited a greater degree of chilling tolerance compared with wild-type plants. Subtractive hybridization was performed to isolate the responsive genes of heterologous Arabidopsis CBF1 in transgenic tomato plants. CATALASE1 (CAT1) was obtained and showed activation in transgenic tomato plants. The CAT1 gene and catalase activity were also highly induced in the transgenic tomato plants. The level of H(2)O(2) in the transgenic plants was lower than that in the wild-type plants under either normal or cold conditions. The transgenic plants also exhibited considerable tolerance against oxidative damage induced by methyl viologen. Results from the current study suggest that heterologous CBF1 expression in transgenic tomato plants may induce several oxidative-stress responsive genes to protect from chilling stress.     

Production and characterization of fertile somatic hybrids of eggplant (Solanum melongena L.) with Solanum aethiopicum L.

Summary In order to produce fertile somatic hybrids, mesophyll protoplasts from eggplant were electrofused with those from one of its close related species, Solanum aethiopicum L. Aculeatum group. On the basis of differences in the cultural behavior of the parental and hybrid protoplasts, 35 somatic hybrid plants were recovered from 85 selected calli. When taken to maturity either in the greenhouse or in the field, the hybrid plants were vigorous, all rapidly overtopping parental individuals. The putative hybrids were intermediate with respect to morphological traits, and all of their organs were larger, particularly the leaves and stems. DNA analysis of the hybrids using flow cytometry in combination with cytological analysis showed that 32 were tetraploids, 1 hexaploid and 2 mixoploids. The hybrid nature of the 35 selected plants was confirmed by a comparison of the isoenzyme patterns of isocitrate dehydrogenase (Idh), 6-phosphogluconate dehydrogenase (6-Pgd) and phosphoglucomutase (Pgm). Chloroplast DNA (ctDNA) restriction analysis using Bam HI revealed that among the 27 hybrid plants analyzed, 10 had S. aethiopicum patterns and the 17 remaining hybrids exhibited bands identical with those of eggplant without any changes. All of the somatic hybrid plants flowered. Both parental plants had 94% stainable pollen, while the hybrids varied widely in pollen viability ranging from 30% to 85%. The somatic hybrids showed high significant variation in fruit production. Nevertheless, there was a tendency for low fertility to be associated often with S. aethiopicum chloroplast type and/or with an abnormal ploidy level, while good fertility was mostly associated with the tetraploid level and eggplant chloroplasts. Interestingly, 2 tetraploid somatic hybrid clones were among the most productive, yielding up to 9 kg/plant. As far as the fertility of the F₁ sexual counterpart was concerned, only 2 fruits of 50 g were obtained. Hybrid fertility in relation to phylogenetic affinities of the fusion partners is discussed.     

Effect of nitrogen application on flowering and yield of eggplant (Solanum melongena L.)

Effect of nitrogen application on number of flowers per plant, number of different types of flowers per plant, length of style, number of fruits per plant and fruit yield/ha of eggplant was investigated under controlled greenhouse conditions. Nitrogen was supplied at 50, 75, 100, 125, 150, 175 and 200 kg N/ha with one control (no nitrogen) treatment. Nitrogen supplied at 200 kg N/ha gave best results and significantly produced the highest number of flowers per plant, fruits per plant and yield (32.24 ton/ha) over control plants. Nitrogen failed to influence style length and type of flowers i.e. long, medium, pseudo-short and short styled flowers. Nitrogen application at 150 and 175 kg N/ha showed comparable results with nitrogen applied at 200 kg N/ha.     

茄子microRNAs与其靶基因的生物信息学预测

microRNAs(miRNAs)是一类在真核生物中发现的长度为21 nt左右、非编码、内源性的单链小分子RNA,通过与靶基因的互补发挥转录后水平的负调控作用。目前,已在许多物种中报道了miRNAs的存在,然而还未见关于茄子miRNAs的报道。根据miRNAs在植物中的高度保守性及其前体的二级结构特征,文章通过同源预测的方法,将已知植物的miRNAs与茄子EST数据库比对,经过一系列的筛选,最终预测到12个家族的16条茄子miRNAs,其中包括3个miRNA家族的正义/反义miRNAs,而miR390和miR399家族的正义/反义miRNAs属于第一次发现。文章还通过在线软件psRNATarget预测到15条茄子miRNAs的71个靶基因,这些靶基因主要编码与茄子生长发育、新陈代谢以及胁迫响应等过程相关的蛋白。     

Allozyme variation in the eggplant,Solanum melongena L. (Solanaceae)

Enzyme electrophoretic studies were made in cultivated Solanum melongena L. (eggplant) and similar wild and weedy forms, several of which have been thought to be different species/taxa. Twenty-nine accessions of S. melongena, 33 accessions of weedy forms (referred to as insanum) and 2 accessions of wild forms (referred to as incanum) were surveyed for 29 isozyme loci. In S. melongena, 22 of the 29 loci were monomorphic, and nearly all of its genes were either also monomorphic or in similar frequencies in insanum and incanum. The results demonstrate that the three taxa have a very close genetic relationship. The high genetic identities between them (0.913–0.967) suggests that they are conspecific even though they include extensive morphological diversity.     

Leaf morphological and ultrastructural performance of eggplant (Solanum melongena L.) in response to water stress

The effects of water stress on leaf surface morphology (stomatal density, size, and trichome density of both adaxial and abaxial surfaces) and leaf ultrastructure (chloroplasts, mitochondria, and cell nuclei) of eggplant (Solanum melongena L.) were investigated in this study. Higher stomata and trichome densities were observed on abaxial surface compared with the adaxial surface. Compared with well watered (WW) plants, the stomata and trichome density of the abaxial surface increased by 20.39% and 26.23% under water-stress condition, respectively. The number of chloroplasts per cell profile was lesser, the chloroplasts became round in a shape with more damaged structure of membranes, the number of osmiophilic granules increased, and the number of starch grains decreased. The cristae in mitochondria were disintegrated. The cell nuclei were smaller and the agglomerated nucleoli were bigger than those of WW plants. Our results indicated that the morphological and anatomical responses enhanced the capability of plants to survive and grow during stress periods.     

Genotype, explant and position effects on organogenesis and somatic embryogenesis in eggplant (Solanum melongena L.)

The relative importance of genotype and explant, and their interactionsfor in vitro plant regeneration via both organogenesis and somaticembryogenesis in Solanum melongena (eggplant) has been studied.Hypocotyl, cotyledon and leaf explants of four commerciallygrown Indian cultivars, Pusa Purple Long, Long White Cluster,Pusa Kranti, and Pusa Purple Cluster were used in the study.A combination of benzyladen-ine (11.1 µM) and indoleaceticacid (2.9 µM) was found to be optimum for shoot regeneration.Naphthalene acetic acid induced embryogenesis in all the threeexplants; 32.2µM was optimum for hypocotyl explants while10.7µM yielded maximum number of somatic embryos fromcotyledon and leaf explants. Genotype, explant and genotype-explantinteraction had highly significant effects on both organogenesisand somatic embryogenesis with genotype exerting maximum effecton both these processes. Pusa Purple Long was found to be themost responsive genotype for regeneration of both adventitiousshoots and somatic embryos among the cultivars. Among the explants,hypocotyls yielded the maximum number of adventitious shootsfollowed by cotyledons and leaves. The embryogenic responseof leaves and cotyledons was, however, significantly higherthan that of hypocotyl explants. Significant differences formorphogenetic potential were also observed within a single explant(hypocotyl). There was a basipetal gradient for organogenesis(i.e. decrease in number of shoots from base to apex) whilethe terminal hypocotyl segments showed better embryogenic potentialthan the median segments. Key words: Solarium melongena, organogenesis, somatic embryogenesis, genotype, explant, position effect     

Callus induction and plantlet formation through culture of isolated microspores of eggplant (Solanum melongena L.)

Morphogenic calli were obtained efficiently from ab initio cultures of isolated microspores in eggplant. Initial culture of freshly isolated microspores in sucrose-free medium at high temperature (35°C) for 3 d was a prerequisite for callus induction. The microspores were re-cultured in modified NLN medium containing 2% sucrose and phytohormones (NAA 0.5 mg l^–1, BA 0.5 mg l^–1) in the dark. After 4 weeks of re-culture, small calli derived from microspores were transferred to MS medium containing 4 mg l^–1 zeatin and 0.2 mg l^–1 IAA for shoot regeneration. The ploidy of 12 randomly selected regenerants was assessed by chromosome counts in root tips. Only one of the regenerants was haploid, 7 were diploid, 3 were triploid and one was tetraploid. The diploids set seeds after self-pollination and showed no segregation for morphological traits in the progeny, suggesting that they were spontaneously doubled haploids.Abbreviations BA 6-benzylaminopurine - NAA 1-naphthaleneacetic acid - IAA indole-3-acetic acid - DAPI 4,6-diamidino-2-phenylindole dihydrochloride     

Anthocyanins, colour and antioxidant properties of eggplant (Solanum melongena L.) and violet pepper (Capsicum annuum L.) peel extracts

Acetone extracts from eggplant (Solanum melongena L.) and violet pepper (Capsicum annuum L.) peels both belonging to the Solanaceae plant family were characterized with respect to their anthocyanin profiles, colour qualities and antioxidant capacities. According to HPLC-DAD-MS3 analyses the major anthocyanin in eggplant was delphinidin-3-rutinoside, while the predominant pigment in violet pepper was assigned to delphinidin-3-trans-coumaroylrutinoside-5-glucoside. Since virtually all anthocyanins were delphinidin-based, the effect of acylation and glycosylation patterns on colour stability and antioxidant capacity could be assessed. Application of two in vitro-assays for antioxidant capacity assessment revealed that eggplant generally exhibited higher values compared to violet pepper which was ascribed to 3,5-diglycosylated structures predominating in the latter. The higher extent of acylation in violet pepper was reflected by a more purplish colour shade of the extracts, but did not translate into a higher stability against fading which again was attributed to additional glycosyl substitution at C5. These findings support the relevance of structure-related activities of anthocyanins both for understanding food colour and their particular nutritional value.