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The chloroplast genomes of wild loquat can help to determine their place in the history of evolution. Here, we sequenced and assembled two novel wild loquat's chloroplast genomes, one is Eriobotrya elliptica, and the other is an unidentified wild loquat, which we named "YN-1". Their sizes are 159,471 bp and 159,399 bp, respectively. We also assembled a cultivated loquat named 'JFZ', its chloroplast genome size is 159,156 bp. A comparative study was conducted with six distinct species of loquats, including five wild loquats and one cultivated loquat. The results showed that both E. elliptica and "YN-1" have 127 genes, one gene more than E. fragrans, which is psbK. Regions trnF-GAA-ndhJ, petG-trnP-UGG, and rpl32-trnL-UAG were found to exhibit high variability. It was discovered that there was a positive selection on rpl22 and rps12. RNA editing analysis found several chilling stress-specific RNA editing sites, especially in rpl2 gene. Phylogenetic analysis results showed that "YN-1" is closely related to E. elliptica, E. obovata and E. henryi. [ABSTRACT FROM AUTHOR]

Loquat is an important commercial specialty fruit tree crop in China, and as a result, there is significant interest in its genetic improvement. Wild loquat, native to China, provides a remarkable genetic resource for breeding improved varieties. Guizhou Province in southwest China contains many natural populations of loquat in its rural areas. In the present study, we analyzed the genetic diversity of native loquat growing throughout Guizhou Province together with wild relatives and domesticated loquat using a set of 20 informative SSR markers. Molecular analysis identified four gene pools, with gene pool I representing cultivated genotypes and gene pool IV containing wild relatives and native surveyed accessions. Approximately 10.8 % of the samples collected from Guizhou Province are feral forms derived from cultivated genotypes, whereas 24.9 % are most closely related to wild species. The remaining 64.3 % of the gene pool is intermediate genotypes derived from spontaneous crosses between wild native forms and cultivated loquat. [ABSTRACT FROM AUTHOR]

Domestication of Uapaca kirkiana Müell. Arg is a high priority for improving rural livelihoods of smallholder farmers in southern Africa. Domestication efforts require knowledge of adaptive traits and intra-specific variation. Morphological traits and amplified fragment length polymorphic (AFLP) markers were used to assess genetic variation in twelve provenances of U. kirkiana collected from southern Africa. Assessment of morphological traits showed significant differences ( P < 0.05) between provenances. Provenances from Zimbabwe and Zambia showed faster growth than those from Malawi (except Phalombe) and Tanzania. Morphological traits exhibited strong genetic differentiation between provenances and within provenances. The degree of provenance differentiation of traits ( Q = 0.03-0.139, Q mean = 0.092) was in the same range with that of AFLP loci ( F mean = 0.089) detected among provenances and within provenances (0.002 < F < 0.259). The differentiation for some morphological traits could be attributed to local adaptation and human selection of the U. kirkiana trees at the site of origin. Mean Nei's ( H) genetic diversity of AFLP showed high diversity within the provenances ( H = 0.181-0.321, H mean = 0.256). An analysis of molecular variance (AMOVA) revealed higher genetic variation (90.8%) within provenances than among provenances (9.2%). There was no geographical pattern of variation in growth and morphological traits among the seed sources. Chipata provenance from Zambia was the most diverse while Mapanzure from Zimbabwe was the least diverse, though it was superior in height and earliest in fruiting. The pattern of genetic diversity indicates low selection in some areas and high gene flow which would be counteracting it. Therefore regional and country collections and conservation strategies should consider differences by focussing on the main range of the species by paying particular attention to unique populations within countries. [ABSTRACT FROM AUTHOR]

Examination of callus micro-grafts in Uapaca kirkiana Müell Arg. was carried out with the objective of determining early signs of graft compatibility. Leaves from U. kirkiana, U. nitida and Jatropha curcas trees were used for callus induction. Two pieces of callus were co-cultured on Murashige and Skoog (MS) medium with different supplements. Co-cultured calli were embedded in paraffin wax and dissected. The specimens were stained in safranin and fast green before viewing under a light microscope. Results showed that MS medium with 0.1 mg l-1 thidiazuron (TDZ) and 0.5 mg l-1 naphthaleneacetic acid (NAA) or 1.0 mg l-1 dichlorophenoxyacetic acid (2,4-D) and 0.5 mg l-1 NAA was effective for callus induction. There were no necrotic layers at the unions within U. kirkiana clones and provenances, but a differential growth (irregularity) between U. kirkiana and U. nitida co-cultured calli. Phenol deposits were observed at the union interfaces of U. kirkiana combinations and were high on calli derived from mature trees. Phenol deposits were absent at the union of J. curcas heterografts. Necrotic layers developed at the unions of U. kirkiana and J. curcas micro-grafts and indicating an outright graft incompatibility. Accumulation of phenol deposits at the union interfaces inhibited graft compatibility in many U. kirkiana combinations. Callus fusion technique can be used to identify partners with an outright graft incompatibility, especially for distant related plant species. [ABSTRACT FROM AUTHOR]