Chenghua (CH) pig and Qingyu (QY) pig are typical Chinese native fatty breeds.  CH pig is mainly distributed in Chengdu Plain, while QY pig is widely distributed throughout the mountain areas around the Sichuan Basin.  There are significant differences in their phenotypic traits, including body image, growth performance, and meat quality.  This study compared several meat quality traits of CH and QY pigs and conducted a genome-wide DNA methylation analysis using reduced representation bisulfite sequencing (RRBS).  It was observed that the pH at 45 min (pH_45min, P=5.22e–13), lightness at 45 min (L*_45min, P=4.85e–5), and lightness at 24 h (L*_24h, P=3.57e–5) of CH pigs were higher than those of QY pigs.  We detected 10 699 differentially methylated cytosines (DMCs) and 2 760 differentially methylated genes (DMGs) associated with these DMCs.  Functional analysis showed that these DMGs were mainly enriched in the AMPK signaling pathway, Type II diabetes mellitus, Insulin signaling pathway, mTOR signaling pathway, and Insulin resistance.  Furthermore, 15 DMGs were associated with fat metabolism (ACACA, CAB39, CRADD, CRTC2, FASN, and GCK), muscle development (HK2, IKBKB, MTOR, PIK3CD, PPARGC1A, and RPTOR), or meat quality traits (PCK1, PRKAG2, and SLC2A4).  The findings may help to understand further the epigenetic regulation mechanisms of meat quality traits in pigs and provide new basic data for the study of local pigs.

North China Plain (NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems.  Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear.  Therefore, increasing the wheat yield in NCP is essential for the national food security.  This study monitored wheat yield, management practices and soil nutrient data in 132 farmers’ fields of Xushui County, Baoding City, Hebei Province during 2014–2016.  These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components (i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield.  Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach.  The results showed that the attainable potential yield for winter wheat was 10 514 kg ha^–1.  The yield gaps varied strongly between three yield groups (i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha^–1, respectively.  For the three yield components, only spikes per hectare was significantly different (P<0.01) among the three yield groups.  For all 132 farmers’ fields, correlation between yield and spikes per hectare (r=0.51, P<0.01), was significantly positive, while correlations with grain number per spike (r=–0.16) and 1 000-grain weight (r=–0.10) were not significant.  The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield.  Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate (26.7%), followed by basal N input (22.1%) and seeding rate (14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare.  For desired spikes per hectare (>6.598×106 ha^–1), the seeding rate should range from 210–300 kg ha^–1, seeding date should range from 3th to 8th October, and basal N input should range from 90–180 kg ha^–1.  Compared to these reasonable ranges of management measures, most of the farmers’ practices were not suitable, and both lower and higher levels of management existed.  It is concluded that the strategies for optimizing yield components could be achieved by improving wheat seeding quality and optimizing farmers’ nutrient management practices in the NCP.

   Loquat (Eriobotrya japonica Lindl.) can be divided into yellow- and white-fleshed cultivars by flesh color. However, a Dongting loquat mutant, which involved bud sport and growing white-fleshed fruit in the central region of the trunk (as wild loquat bears yellow-fleshed fruits naturally), was discovered in the preliminary study. The study cloned the coding sequence (CDS) of NAD⁺-dependent sorbitol dehydrogenase (NAD⁺-SDH ) gene from the selected materials of mutant loquat, wild loquat and other nine loquat cultivars/accessions, and found that the CDS of NAD⁺-SDH gene from the mutant loquat, other than the rest two types of materials, had three single nucleotide polymorphisms (SNPs) loci; in addition, the amino acid encoded at variation loci changed accordingly. NAD⁺-SDH plays an active role in converting sorbitol into fructose in loquat cultivars. For the mutant white-fleshed loquat, the activity of NAD⁺-SDH rises first and then drops, the sorbitol content decreases steadily, and its fructose content is higher than that in wild loquat from coloration to maturation stage. As demonstrated by the real-time fluorescence quantification PCR analysis, the expression level of NAD⁺-SDH gene at maturation stage is about 5-fold lower than wild type. It may be assumed that, the three SNPs loci might lead to excessive conversion of sorbitol into fructose under the catalytic action of NAD⁺-SDH of white-fleshed mutant loquat at maturation stage, resulting in the increase of fructose content and reduced expression abundance of mRNA after transcription. Besides, NAD⁺-SDH gene may be related to flesh color and carbohydrate variation of white-fleshed mutant loquat.