可占用准租金视角下农村集体建设用地流转租赁制改进研究——基于江苏省宜兴市的调查          下载免费PDF全文

王敏  诸培新 《安徽农业大学学报》2021,30(5):23-27

探索如何高效率地解决集体建设用地流转租赁制中可能存在的"敲竹杠"问题，有助于优化我国集体建设用地租赁流转方式。企业生产设备的资产专用性高，产生的可占用准租金高，使企业面临被村集体"敲竹杠"的风险。江苏宜兴市通过流转双方互惠协议和声誉机制等自动实施契约联结，且租赁交易受到第三方干预机制——市政府文件中明确履约保证的约束，共同避免了村集体的"敲竹杠"行为。为促进集体建设用地租赁制健康发展，应借鉴宜兴"长租短约制"，延长租赁期限，稳定租赁关系，避免土地所有者通过抽回土地的威胁来"敲竹杠"。同时，政府应发挥市场规范者的角色，建立清晰的违约责任惩处机制。  相似文献   

Study on PCR rapid molecular detection technique of Meloidogyne vitis          下载免费PDF全文

YANG Yan-mei  LIU Pei  LI Hong-mei  PENG Huan  DU Xia  DONG Ye  HU Xian-qi 《农业科学学报》2022,21(11):3408-3416

Meloidogyne vitis is a new root-knot nematode parasitic on grape root in Yunnan Province, China.  In order to establish a rapid, reliable and specific molecular detection method for M. vitis, the species-specific primers were designed with rDNA-ITS (ribosomal DNA internal transcribed spacer) gene fragment as the target.  The reaction system was optimized and the reliability, specificity and sensitivity of primer were testified, therefore, a rapid PCR detection method for M. vitis was established.  The result showed that the optimal annealing temperature of the primers was 53°C, which was suitable for the detection of different life stages of M. vitis.  Specificity test showed that the specific fragment size of 174 bp was obtained from M. vitis, but other five non-target nematodes did not have any amplification bands, thus effectively distinguish M. vitis and the other five species, and could specifically detect the M. vitis from mixed populations.  Sensitivity test showed that this PCR technique could detect the DNA of a single second-stage juvenile (J₂) and 10^–4 female.  Futhermore, this PCR technique could be used to detect directly M. vitis from soil samples.  The rapid, sensitive and specific PCR molecular detection technique could be used for the direct identification of a single J₂ of M. vitis and the detection of M. vitis in mixed nematode populations and the detection of two J₂s or one male in 0.5 g soil samples, which will provide technical support for the investigation of the occurrence and damage of M. vitis and the formulation of efficient green control strategies.  相似文献