Genome-Wide Association Analysis Identifies Candidate Loci for Callus Induction in Rice ( L.).

Callus induction (CI) is a critical trait for transforming desirable genes in plants. A genome-wide association study (GWAS) analysis was conducted on the rice germplasms of 110 rice accessions, in which three tissue culture media, B5, MS, and N6, were used for the CI of those rice panels' mature seeds. Seven quantitative trait loci (QTLs) on rice chromosomes 2, 6, 7, and 11 affected the CI percentage in the three media.

Differential expression of ethylene biosynthetic and receptor genes in pollination-induced senescence of Dendrobium flowers.

Following successful pollination, Dendrobium orchid flowers rapidly undergo senescence. In Dendrobium cv. Khao Chaimongkol, compatible pollination resulted in faster ethylene production and more rapid development of senescence symptoms, such as drooping, epinasty, venation and yellowing, compared with non-pollinated controls or pollination with incompatible pollinia.

Dendrobium orchids carrying antisense ACC oxidase: small changes in flower morphology and a delay of bud abortion, flower senescence, and abscission of flowers.

Four Dendrobium Sonia 'Earsakul' lines were generated by insertion of one, two or three antisense copies of a Carica papaya gene encoding 1-aminocyclopropane-1-carboxylic acid oxidase (CpACO). Whole vegetative plants of the transgenic lines showed about 50% of the basal ethylene production rate, while the increase in ethylene production in floral buds during opening and open flowers prior to visible senescence was delayed. Detailed analysis of more than 100 parameters in flowering plants showed no effect of antisense ACO on plant morphology and coloration, except for shorter length and width of some of the sepals and petals.

The effect of 1-methylcyclopropene (1-MCP) on expression of ethylene receptor genes in durian pulp during ripening.

Rapid fruit ripening is a significant problem that limits the shelf life of durian, with ethylene having a major impact on the regulation of this event. Durian treated with ethephon ripened 3 d after treatment with increased pulp total soluble solids, ethylene production of the whole fruit and decreased pulp firmness compared to the control fruit. 1-MCP treatment delayed ripening by up to 9 d with inhibited accumulation of total soluble solids, color change, softening and ethylene production.

Ethylene and pollination decrease transcript abundance of an ethylene receptor gene in Dendrobium petals.

We studied the expression of a gene encoding an ethylene receptor, called Ethylene Response Sensor 1 (Den-ERS1), in the petals of Dendrobium orchid flowers. Transcripts accumulated during the young floral bud stage and declined by the time the flowers had been open for several days. Pollination or exposure to exogenous ethylene resulted in earlier flower senescence, an increase in ethylene production and a lower Den-ERS1 transcript abundance.

Molecular analysis of Fiji disease virus segments 2, 4 and 7 completes the genome sequence.

The complete nucleotide sequences of Fiji disease virus (FDV) genome segments S2, S4 and S7 were determined. This now completes the sequencing of all ten dsRNA genome segments of the Fijivirus type member, FDV, which comprises a total of 29339 nt. FDV S2, S4 and S7 comprised 3820, 3568 and 2194 nt, respectively.