Brassica campestris male fertility 19 (BcMF19; GenBank accession number GQ902048.1), a gene that is specially expressed in tapetum cells and microspores during anther development in B. campestris ssp. chinensis, which is learned from the previous in situ hybridization study. In the present study, we constructed antisense-silenced plants of BcMF19 using B. campestris ssp. chinensis to validate this prediction. The morphology of the pistils, long anthers, and short anthers was significantly affected in 35sbcmf19 compared with the control samples. 4´-6-Diamidino-2-phenylindole staining revealed that two generative nuclei and one large vegetative nucleus were not affected in the mutant compared with control. Statistical analysis of Alexander’s staining results showed that 96% of the control pollen grains had vitality, whereas only 86% of the mutant pollen grains did. Under scanning electron microscopy, the mutant demonstrated numerous abnormal pollen grains and resembled dried persimmon. The frequency of normal pollen grains was approximately 18%. Under transmission electron microscopy, the pollen intine during the binucleate and mature pollen stages in 35sbcmf19 exhibited abnormal thickening, especially at the germinal furrows, compared with control. In vitro pollen germination test showed that the tips of the mutant pollen tubes transformed into globular alveoli and stopped growing compared with control. On the other hand, in vivo pollen germination test suggested that BcMF19 affected the pollen tube extension in the pistil. These findings indicate that BcMF19 is essential to the pollen development and pollen tube extension of B. campestris ssp. chinensis.

DNA barcodes have been proposed as a shortcut to provide species identification and as a way to accelerate the discovery of new species. A number of candidate gene regions have been suggested as possible barcodes for animals and plants, but for the identification of recently diverged species and/or varieties with only a few genetic differences it has been reported to be problematic in some cases. This study selected widely cultivated cruciferous vegetables as the primary samples, after failure of discrimination of each species using current DNA barcodes, we performed the fluorescent amplified fragment length polymorphism (F-AFLP) and successfully discriminated each species, subspecies, variety and their cultivar in 74 samples. Then the non-qualitative results obtained from F-AFLP were transformed into two-dimensional barcodes image file of each cultivar via the PDF417 software. This method was also successfully applied to the discrimination of 17 Chinese indigenous pig breeds. The barcode we constructed which greatly reduces the information storage space is genotypes-specific, and can be conveniently decoded into the original data and thereby be conveniently shared and referred to. We believe that it is possible to construct a new data sharing molecular barcode system that could discriminate the subspecies, varieties, cultivars and even individuals with close genetic relationships.