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Capsiate is a key ingredient in the fruits of a nonpungent cultivar of Capsicum annuum. We investigated the effects of a C. annuumextract (CE) and a capsiate-rich fraction of CE (CR) on nuclear receptors involved in multiple signaling pathways, glucose uptake, and adipogenesis in comparison to pure capsiate (Ca). Similar to the effect of Ca (100 μM), CE (500 μg/mL) and CR (100 μg/mL) caused the activation of PPARα and PPARγ (>3-fold), while CR also activated LXR and NRF2 (>2 fold). CR (200 μg/mL) and Ca (100 μM) decreased lipid accumulation (22.6 ± 14.1 and 49.7 ± 7.3%, respectively) in adipocytes and increased glucose uptake (44.7 ± 6.2 and 30.1 ± 12.2%, respectively) in muscle cells and inhibited the adipogenic effect induced by rosiglitazone by 41.2 ± 5.6 and 13.9 ± 4.3%, respectively. This is the first report to reveal the agonistic action of CR and Ca on multiple nuclear receptors along with their enhanced glucose uptake and antiadipogenic effects. The results indicate the potential utility of the capsiate-rich fraction of C. annuumin alleviating the symptoms of metabolic syndrome and in preventing the undesired adipogenic effects of full PPARγ agonists such as rosiglitazone.

Scanning electron and light microscopy were used to examine pollen of the currently recognized species (and forms) within the genus Citrullus(Cucurbitaceae). Materials examined included: C. lanatus(Thunb.) Matsum. & Nakai, the citron (C. amarusSchrad.), the egusi [C. mucosospermus(Fursa) Fursa], C. colocynthis(L.) Schrad., C. rehmiiDe Winter, C. ecirrhosusCogn., and the gemsbok cucumber [C. naudinianus(Sond.) Hook. f.]—also referred to in the literature as Acanthosicyos naudinianus(Sond.) C. Jeffrey. Pollen of all species were similar in shape differing slightly in their polar (P) and equatorial (E) axes and P/E. In general, all were characterized as prolate and tricolpate with a small polar area and reticulate ornamentation. Flow cytometry revealed C values for the taxa examined as ranging from 0.8 to 1.04 pg DNA per 2C nuclei. A mutant affecting pollen ornamentation was identified in PI 482261, a C. amaruscitron from Zimbabwe. Pollen ornamentation on PI 482261 was rugulate. An examination of 15 additional accessions from neighboring areas in Zimbabwe revealed a second rugulate type in PI 482312, while the remaining 14 C. amarusaccessions were reticulate. Successful hybridizations were made between C. colocynthis(PI 652554) and C. naudinianus(GRIF 14032), and between C. rehmii(PI 670011) and C. naudinianus(GRIF 14032). The F1hybrids of both crosses were extremely vigorous and exhibited some characteristics (i.e., branching and storage root formation) associated with the male parent. Other characteristics such as tendril length and shape, and leaf size and shape, were intermediate between the parents. To date, the interspecific F1hybrids have produced only shrunken (nonviable) pollen.

Abstract.: Pierce's disease (PD, Xylella fastidiosa) of grapevine is the primary pathogen limiting vinifera grape production in Florida and other regions of the southeastern United States. Quick and accurate detection of PD strains is essential for PD studies and control. A unique random amplified polymorphic DNA (PD1-1-2) was isolated from a PD strain from Florida. Fragment PD1-1-2 was cloned, sequenced, and found to be 1005 bp in length. PCR primers were designed to utilize these sequence data for PD strain detection. One primer set (XF176f–XF954r) amplified a 779-bp DNA fragment from 34 PD strains including seven pathotypes of X. fastidiosa, but not from strains of Xanthomonas campestris pv. campestris, Xan. vesicatoria or Escherichia coli. A second primer set (XF176f and XF686r) amplified a 511-bp fragment specific to 98 PD strains, but not from strains of citrus variegated chlorosis, mulberry leaf scorch, oak leaf scorch, periwinkle wilt, phony peach, or plum leaf scald. Sequence analysis indicated that RAPD fragment PD1-1-2 contains a Ser-tRNA gene. The PD-specific region includes a TaqI restriction site (TCGA) and is 150 bp downstream of the Ser-tRNA gene.

The inhibitory effects of abscisic acid (ABA) on in vitro growth and development of axillary buds from nodal segments of sweet potato (Ipomoea batatas L.) was investigated. ABA at concentrations of 0.01, 0.1, 1.0 or 10.0 mg 1-1 inhibited axillary bud and root development and subsequent plantlet growth. ABA at 10 mg 1-1 completely inhibited axillary shoot development but did not affect the viability of cv. Jewel explants over a culture period of 365 days. Transfer of nodal segments cultured for 90, 180 or 365 days from basal medium containing 10 mg 1-1 ABA to growth regulator-free media resulted in rapid and normal plantlet development. Gibberellic acid at 0.1, 1.0 or 10.0 mg 1-1 in the presence of ABA at 0.1, 1.0 or 10.0 mg 1-1 did not counteract the ABA-induced growth inhibition. Although ABA totally inhibited the growth of 6 sweet potato plant introductions at a concentration of 10.0 mg 1-1, the efficacy of ABA as a suppressant of shoot growth varied with genotype.

An efficient protocol has been developed for protoplast culture and plant regeneration from wild peanut (A. paraguariensis) using a nurse culture method. Protoplasts were isolated from suspension cultures initiated from leaf-derived callus, imbedded in agarose blocks and co-cultured with nurse cells of the same species. Up to 10% of the protoplasts divided and formed compact callus colonies. The protoplast plating efficiency was correlated with both the length of the nurse cell co-cultivation period and the protoplast plating density. The optimal nurse culture duration was 14 d. The optimal plating density was 2×104 protoplasts/ml plating medium. Multiple shoots (up to 10 shoots per colony) were readily regenerated from protoplast-derived callus after transfer of callus to semi-solid modified MS medium containing 0.5 mg l-1 NAA and 1 mg l-1 BA. Plantlets with normal leaflets were obtained by rooting shoots on porous rootcubes saturated with modified MS medium containing 1 mg l-1 NAA.

The polymerase chain reaction (PCR) was used to detect polymorphisms among 29 diploid clones of Musa acuminata Colla. from Papua New Guinea. Primer sequences were derived from a 520 bp highly repetitive DNA sequence isolated from M. acuminata ssp. malaccensis. Primers, used individually, detected a total of 48 polymorphisms that were scored as unit characters and used to generate a Jaccard's similarity index. Principal coordinate analysis (PCO) was used to cluster clones and the unweighted paired-group method of analysis (UPGMA) was used to compute genetic distance among the materials examined. The abundance of diversity within the PNG diploids examined reflects the extreme genetic variability within the M. acuminata gene pool. PCR, utilizing primers from a highly repetitive sequence, is a rapid means of detecting genetic diversity in M. acuminata.

The triploid genome of plantain (Musaspp., AA group) has been considered intractable to genetic improvement because of the production of putatively homogeneous 2n(= 3x) gametes. Plantain breeding schemes have been based on the hybridization of 2n megaspores from the triploid plantain and haploid microspores from a wild diploid banana. The resultant fuli‐sib populations of tetraploid hybrids exhibited extreme variation in phenotypic characteristics. This study was conducted to analyze the genetic constitution of tetraploid hybrids in order to characterize the nature of the gametes from which they were derived. Parental genotypes were screened with 31 primer pairs specific to different Musamicrosatellite loci. Primers which detected polymorphisms between the parental genotypes were used to screen a population of 14 full‐sib tetraploid hybrids. A subset of primers was also used to screen a population generated by self‐pollination of the parental diploid banana. During analysis of the tetraploid hybrid population, 75% of the alleles donated by the maternal genotype (Obino l'Ewai) were observed to segregate. These data demonstrate the occurrence of recombination during the formation of 2nmegaspores in triploid plantain. Analysis of the paternal diploid banana accession (Calcutta 4) and its selfed progeny suggests that this accession is highly heterozygous. These data demonstrate the importance of genetic characterization to Musabreeding, and also indicate that microsatellite markers are well suited for marker‐assisted selection systems in Musa.

Random genomic probes were used to detect restriction fragment length polymorphisms (RFLPs) in 26 accessions of Musa representing eight species from Papua New Guinea (PNG), M. textilis, M. jackeyi and one accession of Ensete. Ninety-eight phylogenetically informative characters were scored and analyzed cladistically and phenetically. Results generally agreed with previous morphology-based phylogenetic analyses. However, the closest wild relative of the edible M. fehi (fe'i banana) appears to be M. lolodensis. Musa angustigemma is sister species with M. boman and M. jackeyi and is distinct from M. peekelii, with which it is often united. Musa boman is unambiguously placed in section Australimusa. The diploid parthenocarpic landraces of section Musa unique to PNG are closely related to, but apparently distinct from, M. acuminata ssp. banksii. The evolution of the fe'i bananas and the M. acuminata-derived diploid landraces of PNG are discussed.

Fertile transgenic plants of peanut (Arachis hypogaea L. cv. New Mexico Valencia A) were produced using an Agrobacterium-mediated transformation system. Leaf section explants were inoculated with A. tumefaciens strain EHA105 harboring the binary vector pBI121 containing the genes for ß-glucuronidase (GUS) and neomycin phosphotransferase II (NPTII). Approximately 10% of the shoots regenerated on selection medium were GUS-positive. Five independent transformation events resulted in the production of 52 fertile transgenic peanut plants. On average, 240 d were required between seed germination for explant preparation and the production of mature t1 seed by T0 plants. Molecular analysis of transgenic plants confirmed the stable integration of the transgenes into the peanut genome. GUS expression segregated in a 3:1 Mendelian ratio in most T1 generation plants.