Distribution system will affect the labor incentive that has been heatedly discussed by recent literatures. Using a unique micro dataset, this paper demonstrates that the equalitarian distribution system is one of the reasons for the insufficient labor incentive during the Chinese Collective Agriculture period. Specifically speaking, in the distribution of basic rations, the proportion for children (aged 1–3 and 4–7 years) was often beyond their nutrition demand, resulting the dissatisfaction of other families with more laborers and less children, thus these households will reduce their labor supply gradually. At the same time, the existence of outstanding accounts makes it a failure to use work points to buy distributions, which is the mechanism of the distribution system and insufficient labor incentive. All the results have been accepted by the robustness tests. The study will help to understand the distribution system and labor incentive, as well as the failure of the Chinese collective agriculture.

Maize is one of the most important crops worldwide, but it suffers from salt stress when grown in saline-alkaline soil. There is therefore an urgent need to improve maize salt tolerance and crop yield. In this study, the SsNHX1 gene of Suaeda salsa, which encodes a vacuolar membrane Na⁺/H⁺ antiporter, was transformed into the maize inbred line 18-599 by Agrobacterium-mediated transformation. Transgenic maize plants overexpressing the SsNHX1 gene showed less growth retardation when treated with an increasing NaCl gradient of up to 1%, indicating enhanced salt tolerance. The improved salt tolerance of transgenic plants was also demonstrated by a significantly elevated seed germination rate (79%) and a reduction in seminal root length inhibition. Moreover, transgenic plants under salt stress exhibited less physiological damage. SsNHX1-overexpressing transgenic maize accumulated more Na⁺ and K⁺ than wild-type (WT) plants particularly in the leaves, resulting in a higher ratio of K+/Na+ in the leaves under salt stress. This result revealed that the improved salt tolerance of SsNHX1-overexpressing transgenic maize plants was likely attributed to SsNHX1-mediated localization of Na⁺ to vacuoles and subsequent maintenance of the cytosolic ionic balance. In addition, SsNHX1 overexpression also improved the drought tolerance of the transgenic maize plants, as rehydrated transgenic plants were restored to normal growth while WT plants did not grow normally after dehydration treatment. Therefore, based on our engineering approach, SsNHX1 represents a promising candidate gene for improving the salt and drought tolerance of maize and other crops.

The biological chemistry would be responsible for the meat quality. This study tried to investigate the transcript expression profile and explain the characteristics of differentially expressed genes between the Wujin and Landrace pigs. The results showed that 526 differentially expressed genes were found by comparing the transcript expression profile of muscle tissue between Wujin and Landrace pigs. Among them, 335 genes showed up-regulations and 191 genes showed down-regulations in Wujin pigs compared with the Landrace pigs. Gene ontology (GO) analysis indicated that the differentially expressed genes were clustered into three groups involving in protein synthesis, energy metabolism and immune response. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis found that these differentially expressed genes participated in protein synthesis metabolism, energy metabolism and immune response pathway. The Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis of protein function and protein domains function also confirmed that differentially expressed genes belonged to protein synthesis, energy metabolism and immune response. Genes related protein synthesis metabolism pathway in Landrace was higher than in Wujin pigs. However, differentially expressed genes related energy metabolism and immune response was up-regulated in Wujin pigs compared with Landrace pigs. Quantitative real-time RT-PCR on selected genes was used to confirm the results from the microarray. These suggested that the genes related to protein synthesis, energy metabolism and immune response would contribute to the growth performance, meat quality as well as anti-disease capacity.