"‘Zi Mo Xian’: A New Summer Iris Induced by Heavy Ions" published on Feb 2023 by American Society for Horticultural Science.

Litchi (Litchi chinensis Sonn.) is a popular subtropical fruit with a red pericarp that is primarily determined by the accumulation of anthocyanins. The peel color and fruit quality are also influenced by proanthocyanins (PAs), which play roles in fruit development and postharvest quality. In this study, we identified LcMYB2 as a key regulator of both anthocyanin and PA biosynthesis in litchi. Phylogenetic analysis revealed that LcMYB2 belongs to the VvMYB5 subclade. Expression analysis showed that LcMYB2 is highly expressed in the early stages of fruit development. Its expression pattern was consistent with that of LcLAR and LcANR, two key genes in the PA biosynthetic pathway. Subcellular localization and protein–protein interaction assays confirmed that LcMYB2 localizes to the nucleus and interacts with LcbHLH3. Dual-luciferase reporter assays demonstrated that the LcMYB2-LcbHLH3 complex activates the promoters of LcLAR and LcANR, supporting its role in regulating PA biosynthesis. Furthermore, overexpression of LcMYB2 in tobacco resulted in the synthesis of anthocyanins and PAs in the flower, indicating that LcMYB2 can regulate anthocyanin and PA biosynthesis. Additionally, transgenic tobacco plants with LcMYB2 overexpression exhibited delayed anther dehiscence, suggesting a broader role in plant development. These findings highlight the multifunctional nature of LcMYB2 in regulating both anthocyanin and PA biosynthesis, as well as its involvement in reproductive development.

"‘Chu Xin’: A New Showy Pink Flowered Candy Lily Cultivar" published on Jun 2024 by American Society for Horticultural Science.

For Fragaria (strawberry) species, individual chromosome identification is challenging due to the small size of chromosomes; consequently, the chromosome numbers of most cultivars remain unreported. In this study, we investigated the ploidy of 26 strawberry cultivars by counting root-tip chromosomes. Surprisingly, 25 cultivars were octoploid (2n = 8x = 56), whereas only ‘Tokun’ was aneuploid (2n = 10x − 3 = 67). To explore the breeding potential of this aneuploid, we performed reciprocal crosses between ‘Tokun’ and ‘Benihoppe’, a widely cultivated octoploid cultivar. Only the combination with ‘Benihoppe’ as female and ‘Tokun’ as male produced fertile progenies. The progenies had variable chromosome numbers of 61, 62 or 63, meaning that ‘Tokun’ produced aneuploid gametes with varying chromosome numbers ranging from 33 to 35. Some hybrids exhibited superior aroma, firmness, or soluble solids compared with their parents. Specifically, J2138 (2n = 9x − 2 = 61) was selected for its larger single-fruit weight, J2139 (2n = 9x − 2 = 61) and J2153 (2n = 9x − 2 = 61) for their white flesh, and J2151 (2n = 9x − 1 = 62) and J2156 (2n = 9x = 63) for their soluble solids content exceeding that of the higher parent, showing potential value for commercial production and breeding. Strawberry is usually propagated via stolons or through tissue culture; therefore, aneuploids obtained from 8x × aneuploid ‘Tokun’ crosses would be good sources for cultivar breeding.