Malus prunifolia Borkh. ‘Fupingqiuzi’ has significant ecological and economic value and plays a key role in germplasm development and resistance research.  However, its long juvenile phase and high heterozygosity are barriers to the identification of ‘Fupingqiuzi’ progeny with excellent traits.  In-vitro regeneration techniques and Agrobacterium-mediated genetic transformation systems can efficiently produce complete plants and thus enable studies of gene function.  However, optimal regeneration and genetic transformation systems for ‘Fupingqiuzi’ have not yet been developed.  Here, we evaluated the factors that affect the in-vitro regeneration and transformation of ‘Fupingqiuzi’.  The best results were obtained when transverse leaf sections were used as explants, and they were grown in dark culture for three weeks with their adaxial sides contacting the culture medium (MS basal salts, 30 g L⁻¹ sucrose, 8 g L⁻¹ agar, 5 mg L⁻¹  6-benzylaminopurine (6-BA), 2 mg L⁻¹ thidiazuron (TDZ), and 1 mg L⁻¹ 1-naphthlcetic acid (NAA), pH 5.8).  A genetic transformation system based on this regeneration system was optimized: after inoculation with A. tumefaciens solution for 8 min, 4 days of co-culture, and 3 days of delayed culture, the cultures were screened with cefotaxime (150 mg L⁻¹) and kanamycin (15 mg L⁻¹).  We thus established an efficient regeneration and genetic transformation system for ‘Fupingqiuzi’, enabling the rapid production of transgenic material.  These findings make a significant contribution to apple biology research

Genetic diversity, population structure, and population expansion of goats worldwide (4 165 individuals from 196 breeds) were analyzed using published mitochondrial DNA (mtDNA) D_loop hypervariable region sequences. Results showed that 2 409 haplotypes and 301 polymorphic sites were present within the 401-bp length D_loop region, the nucleotide diversity (Pi) was 0.03471, and the haplotype diversity (Hd) was 0.9983. Phylogenetic analysis revealed that 98.92% of haplotypes were divided into six obvious clusters, consistent with the classification of the known mitochondrial haplogroups of goats. Haplogroup A accounted for the largest proportion (86%). Interestingly, two unknown divisions (Unknown I and Unknown II) were discovered from goats in Southwest China, suggesting that Southwest China has unique maternal haplogroups. Analysis of molecular variance (AMOVA) and the average number of pairwise differences between populations (PiXY) indicated that geographical variation was small but significant. Neutrality tests (Tajima’s D and Fu’s F_S tests) and mismatch distribution showed that haplogroups B, C, and G had expansion histories. In addition, the phylogenetic relationship between domestic and wild goats suggested that Capra aegagrus is the most likely wild ancestor and may have participated in the domestication of ancestral populations of A, B, C, and F haplogroups. A meta-analysis on the mtDNA sequences of goats from international databases was conducted to analyze goats’ genetic diversity, population structure, and matrilineal system evolution worldwide. The results may help further understand the domestication history and gene flow of goats worldwide.