Solanum Melongena Cv Research Articles

Specific sequence modifications of a cry3B endotoxin gene result in high levels of expression and insect resistance.

Solanum melongena (eggplant) cv. Picentia and the wild species Solanum integrifolium were transformed with both a wild type (wt) and four mutagenized versions of Bacillus thuringiensis (Bt) gene Bt43 belonging to the cry3 class. The Bt gene was partly modified in its nucleotide sequence by replacing four target regions (W: +1 to +170; X: +592 to +1057; Y: +1203 to +1376; Z: +1376 to +1984) with synthetic fragments obtained by polymerase chain reaction amplification of crude oligonucleotides. The synthetic Bt genes were designed to avoid, in their modified regions, sequences such as ATTTA sequence, polyadenylation sequences and splicing sites, which might destabilize the messenger RNA. Furthermore, the codon usage was improved for a better expression in the plant system. The amino acid composition was not altered. Four versions of the modified Bt gene were obtained, BtE, BtF, BtH and BtI, with a nucleotide subtitution percentage of 8.2, 8.6, 14, and 16%, respectively, in comparison to the wt gene Bt43. Modified versions contained different subsets of substituted regions: BtE-W + Z, BtF - Y + Z, BtH-X + Y + Z, BtI - W + X + Y + Z. In the final modified version (BtI), overall guanine+cytosine was increased from the 34.1% of the wt gene to 45.5%, and most of the destabilizing sequences were eliminated. Transgenic plants obtained with the more modified versions, BtH and BtI, were fully resistant to Leptinotarsa decemlineata Say first- and third-instar larvae, while Bt43 wt, BtE and BtF genotypes did not cause mortality and did not affect larval development.

Are chlorophylls good indicators of nitrogen and phosphorus levels?1

Abstract Aubergine plants (Solanum melongena cv. Bonica) were grown under controlled greenhouse conditions on a soil substrate supplied with organic fertilizers (15 kg/m2) mixed with calcium sulfate (CaSO4 at 500 g/m2), with different doses of nitrogen (N as N1 = 15, N2 = 22.5, N3 = 30 g/m2) in the form of ammonium nitrate (NH4NO3), and phosphorus (P as P1 = 24, P2 = 36 g/m2) as phosphorus acid H3PO4). Plants were sampled every 15 days, and the pigments chlorophyll a, chlorophyll b, total (a+b) and ratio (a/b), carotene, licopene, and anthocyanins were determined in the leaves. The results showed that increases in rhizosphere N led to increases in foliar concentrations of chlorophyll a and b, both individually and as total chlorophyll, independently of the dose of P applied. Total chlorophyll concentrations were directly correlated with the level of P fertilization. Carotene and licopenes reflected the influence of increasing doses of N, whereas P did not affect these pigments. Anthocyanin levels were affected by both N and P.

DRIP/TRICKLE FERTILIZING EGGPLANT

The effectiveness of varying rates and timing of applied primary plant nutrients as a completely soluble N-P-K fertilizer through a drip/trickle low volume irrigation system was studied during 1991 on eggplant (Solanum melongena cv. Harris Special Hibush). Before the drip irrigation tubing and black plastic mulch were laid on a coastal plain sandy loam soil, plots were treated with 0, 22, 45, and 67 kg ha-1 of nitrogen (N), phosphate (P2O5) and potash (K20). The higher rates of preplant fertilization did have a significant beneficial effect on total seasonal yields of quality eggplants. The preplant treatments also had an influence on mid and late season production. As the frequency of drip/trickle applied primary plant nutrients increased up to 6 seasonal applications, the total quality fruit production substantially increased. Frequency of applications also had an influence on seasonal yields. Applying increased rates of the primary plant nutrients at a low seasonal frequency of 3 applications had little influence on increasing total quality yields of eggplants. Individual quality fruit was significantly heavier from plants which received 5 to 6 applications of the soluble N-P-K fertilizer than from plants which received no fertilizer through the drip/trickle irrigation system for the season.

Chromosome association and pollen fertility in Solanum melongena*S. surattense hybrids.

Intraspecific and interspecific relationship between Solanum melongena cv. Dorli, Round Black and S. surattense was investigated. Chromosome association and pollen sterility were also calculated for the parent and hybrids. The hybrid Dorli×surattense was possible only when the former was female parent. The fruits were obtained when the crosses were attempted between Round Black×Dorli but with sterile seeds. Some of these hybrids did not survive up to the flowering age. Round Black×surattense was unsuccessful in either direction. Cytological studies showed univalents frequently at diakinesis and metaphase I in the hybrid plants but not so in their parents. The univalents were due to the absence of pairing between homologous chromosomes. Laggards varying from 2 to 4 and bridges were observed in the hybrid plants.

Organogenesis in tissue culture of Solanum melongena cv. Florida Market

Cell suspension cultures were initiated from pith callus of eggplant, Solanum melongena cv. Florida Market on Murashige and Skoog (MS) medium supplemented with 13.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of mineral salts (MgSO 4, KNO 3, CaCl 2), sucrose and 2,4-D were studied on aggregate formation in suspension cultures. Aggregates from a cell suspension when cultured on an MS agar medium supplemented with various concentrations and combinations of indole-3-acetic acid (IAA) and γ,γ-isopentenyl adenine (2iP) differentiated into green nodules, but they failed to develop into organized shoots on the same medium. Upon transfer of these green nodules to MS medium supplemented with 0.1 μM ascorbic acid (autoclaved with the medium) alone or in combination with 49 μM 2iP, developed further into organized leafy shoots. This suggests that some degradation product of ascorbic acid might be responsible for inducing leafy shoots. Based on leaf morphology and chromosome analysis, regenerated plants were identified as tetraploids.