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Seed coat-induced dormancy protects embryos from environmental conditions, and delays seed germination. In this study, we developed a simple method to accelerate embryo germination. That is, pear s...

Here, the L-ascorbic acid (AsA) content as well as activities of enzymes and genes in AsA biosynthesis were investigated in bagged and unbagged fruit of Pyrus pyrifolia ‘Cuiguan’ during on-tree dev...

In this study, we reported the identification, structural characteristics, phylogenetic, and expression patterns of 6 TMT genes (PbTMT1 to PbTMT6) in Pyrus bretschneideri. The 6 PbTMT genes were located on chromosomes 6, 5, 5, 10, 15, and 15, respectively. Analysis of the exons/introns revealed that all 6 genes contain the same exons and display a high degree of conservation with corresponding TMT genes in other plant species. Comparative screening of the motifs in PbTMT proteins indicated high conservation in terms of number, width, and order of motifs, which indirectly indicated that the 6 PbTMT proteins are indeed members of the TMT gene family. Phylogenetic analysis revealed that PbTMTs exhibited the greatest homology with those of Malus domestica. Analysis of expression levels of the 6 PbTMT genes revealed that transcripts of PbTMT5 were nearly undetectable in seeds but were highly expressed in stems and flowers. The other PbTMTs were differentially expressed in all tissues. PbTMT1 exhibited ...

The magnesium ion (Mg2+) is the most abundant divalent cation in living cells, and it plays essential roles in various cellular functions. Mg2+ homeostasis in plant cells is crucial for plant growth. The MRS2/MGT family of proteins localise to various membranes, and they function during Mg2+ transport in plants, but their functions are largely unknown in fruit trees. In this study, we performed a genome-wide analysis to identify the MGT gene family members in the pear Pyrus bretschneideri. Sixteen MGT genes were identified. Analysis of the activity of pear pollen showed that a low-concentration magnesium ion treatment was beneficial for pollen germination and pollen tube growth. None of the 16 MGT genes were expressed in any unique tissue, including pollen, and their expression in magnesium-treated pollen varied greatly, where PbrMGT7 was the most sensitive and it was tested as a representative. PbrMGT7 could functionally complement a bacterial strain deficient in Mg2+, thereby indicating a role i...

Flower buds are very important for pear yield; non-germinated flower buds become wizened and drop from the branch, reducing pear production. However, little research has focused on the study of wizened flower bud (WB) formation in spring. In order to elucidate the mechanism of WB formation in pear, physiological indices relating to plant hormones and antioxidases were measured. We found that activities of peroxidase (POD) and superoxide dismutase (SOD) were higher and lower, respectively, in WBs than in normal flower buds (NBs). The contents of indole acetic acid (IAA), gibberellin (GA), and cytokinin (CTK) were lower in WBs, while the level of addition of abscisic acid (ABA) was higher in WBs than in NBs. Differentially expressed genes (DEGs) were surveyed between WBs and NBs. In total, 23 DEGs relating to POD and SOD were detected from GO (Gene Ontology) enrichment, and 29 DEGs associated with plant hormone biosynthesis were found from the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway. ...

SummaryOne-hundred and six accessions of Pyrus, including 87 local Chinese accessions of P. pyrifolia, were identified genetically using nine microsatellite (simple sequence repeat) loci developed from apple and pear. A total of 147 putative alleles were obtained. Among the 106 accessions, 100 could be differentiated successfully, except for three pairs of synonymous accessions or mutants. For the 87 accessions of Chinese P. pyrifolia, the number of putative alleles per locus ranged from ten to 21, with an average of 15.3. The observed heterozygosity and polymorphic information content were 0.60 and 0.75, respectively. A phenogram based on the SSR genotypes was obtained. The 87 accessions of Chinese P. pyrifolia clustered into seven groups, based on their geographical origin. Most P. bretschneideri cultivars grouped together with the P. pyrifolia accessions from the same geographical areas. Some Japanese pear cultivars (i.e., ‘Choujuurou’, ‘Housui’, ‘Niitaka’, ‘Okusankichi’, and ‘Shinseiki’) grouped toget...

Six selected antioxidants (catechin, quercetin-3-galactoside, cyanidin-3-glucoside, pelargonidin-3-glucoside, ellagic and gallic acids) were evaluated in vitro for their antifungal activities and mode of action on Botrytis cinerea Pers., one of the most important pathogens of strawberries. Inhibitory effects were found for all the tested antioxidants, but varied at different fungal developmental stages. Catechin and quercetin-3-galactoside showed linear inhibitory effects on germ tube elongation, with the highest suppression ratios of 54.8% and 58.8% respectively. No significant effect was found on spore germination between treatments and control. Gallic acid showed very strong and linear inhibition on spore germination (r = −0.95), but the effect diminished after spore germination. Cyanidin-3-glucoside and pelargonidin-3-glucoside provided effective control on the fungi as concentrations increased. The arresting effect of ellagic acid on development of B. cinerea was quadratic. Ellagic acid inhibited ger...

Well-dispersed MoS2 micro-spheres with the diameters of 0.5∼1.5 µm have been successfully synthesized via the extraction-solvothermal method. The ions were extracted into hexane by the extractant Cyanex 302 (di-(2,4,4-trimethylpentyl) monothiophosphinic acid) firstly, then the extracted solution was given solvothermal treatment to synthesize MoS2 at 150 °C for 24 hours. The obtained samples was characterized by XRD, EDS, SEM, TEM, and HRTEM technologies, respectively. Results indicated that Cyanex 302 acted as phase transferring agent, reductant, sulfur source and morphology-controlling agent in the whole procedure. Moreover, the tribological properties of liquid paraffin (LP) containing the as-prepared MoS2 micro-spheres were also evaluated on a four-ball machine and the chemical states of some typical elements on the worn surfaces were examined with XPS, showing that the MoS2 product was an excellent oil additive in LP with good anti-wear and friction-reducing properties.

The friction and wear properties of MoS 2 micro-sized spheres (MS-MoS2) modified by Cyanex 302 (bis(2,4,4-trimethylpentyl) monothiophosphinic acid) as additive in liquid paraffin (LP) were studied and compared with those of commercial colloidal MoS 2 (CC-MoS 2 ) on a four-ball tester and an Optimol SRV oscillating friction and wear tester in a ball-on-disc contact configuration. The worn surfaces were examined with SEM and XPS, respectively. The results showed that the Cyanex 302-modified MS-MoS 2 was a better extreme-pressure and antiwear and friction-reducing additive in LP than CC-MoS 2 . The boundary lubrication mechanism could be deduced as the effective chemical adsorption film formed by the alkyl and active elements (S, O, and P) in Cyanex 302 and tribochemical reaction and deposition film containing MoS 2 , Fe 2 O 3 , and FePO 4 . Moreover, the coexistence of sliding and rolling frictions in the lubricant of MS-MoS 2 /LP also contributed to the enhanced tribological properties.

SummaryTo investigate fruit set after self-pollination at different floral stages, and its relationship to the S-RNase content of the style in Japanese apricot, which exhibits gametophytic self-incompatibility (GSI), the cultivar ‘Xiyeqing’ was selfand cross-pollinated at –6, –4, –2, 0 and +2 d after anthesis (DAA). At –6 and –4 DAA, the percentage fruit set was low, suggesting that the propensity to seed set was weak during this period. At –2 DAA, the percentage fruit set, after self-pollination, reached a maximum of 5.97%. Thus, the effective time of self-pollination to obtain inbred seed was –2 DAA. Soluble protein extracts of styles at each floral stage were subjected to iso-electric focussing. The results showed that S-RNase began to be synthesized from –6 DAA, reached its maximum expression 2 – 3 d before anthesis, and was degraded slowly after anthesis. The number of pollen-tubes arriving at the stylar base, as detected by fluorescence microscopy, varied at –2, 0, and +2 DAA. The number of pollen-t...