Relationship between Sustainable Land Use and Rural Economic Development:A Case Study of Meining Village,Pingma Town in Guangxi

For a long time,rural economic development has put economic benefits in the first place,ignoring the impact of unreasonable land use on local land resources and ecological environment,which is not conducive to the long-term high-quality development of local economy and sustainable land use.There is an urgent need to study the relationship between sustainable land use and rural economic development in order to achieve the coordinated development of the two.By using the methods of literature research and field investigation,this paper studies Meining Village,Tiandong County,Guangxi Zhuang Autonomous Region.The study found that farmers tend to plant pure eucalyptus forest,single land use structure,short-term rotation planting model and traditional afforestation and land preparation technology are not conducive to sustainable land use in forest areas,and affected by economic and educational factors,farmers livelihood is relatively simple,so the development of rural economy will be restricted.In view of the above problems,this paper puts forward the following solutions:changing the land use model of Meining Village to promote sustainable land use;introducing advanced science and technology and diversified livelihood ways to promote the sustainable development of rural economy;building a virtuous circle of sustainable land use and rural economic development.

A new gain-of-function OsGS2/GRF4 allele generated by CRISPR/Cas9 genome editing increases rice grain size and yield

Grain size is one of the most important factors affecting rice grain quality and yield,and attracts great attention from molecular biologists and breeders.In this study,we engineered a CRISPR/Cas9 system targeting the miR396 recognition site of the rice GS2 gene,which encodes growth-regulating factor 4(OsGRF4)and regulates multiple agronomic traits including grain size,grain quality,nitrogen use efficiency,abiotic stress response,and seed shattering.In contrast to most previous genome editing efforts in which indel mutations were chosen to obtain null mutants,a mutant named GS2^(E) carrying an in-frame 6-bp deletion and 1-bp substitution within the miR396-targeted sequence was identified.GS2^(E) plants showed increased expression of GS2 in consistent with impaired repression by miR396.As expected,the gain-of-function GS2^(E) mutant exhibited multiple beneficial traits including increased grain size and yield and bigger grain length/width ratio.Thousand grain weight and grain yield per plant of GS2^(E) plants were increased by 23.5%and 10.4%,respectively.These improved traits were passed to hybrids in a semidominant way,suggesting that the new GS2^(E) allele has great potential in rice improvement.Taken together,we report new GS2 germplasm and describe a novel gene-editing strategy that can be widely employed to improve grain size and yield in rice.This trait-improvement strategy could be applied to other genes containing miRNA target sites,in particular the conserved miR396-GRF/GIF module that governs plant growth,development and environmental response.

Multilevel profiling and identification of Dalbergia odorifera and Dalbergia stevensonii by FTIR,NMR and GC/MS

As a rare and valuable wood and herbal material, Dalbergia odorifera is often counterfeited by Dalbergia stevensonii in the market. For the confident chemical identification of D. odorifera and D. stevensonii, the ethanol-benzene extractives are characterized by multiple metabolomics tools, including Fourier transform infrared （FTIR） spectroscopy, nuclear magnetic resonance （NMR）, and gas chromatography- mass spectrometry （GC/MS）. Conventional FTIR spectroscopy, second derivative infrared （SD-IR） spectroscopy and two-dimensional correlation infrared （2D-IR） spectroscopy are combined to interpret the functional groups of the ethanol-benzene extractives. Fingerprint-like characteristics make FTIR a rapid and accurate method to distinguish D. odor/fera from D. stevensonii. Chemical differences of the extractives revealed by FrIR methods can be further confirmed by ^1H NMR and ^13C NMR. Meanwhile, the volatile compounds in the extractives can be identified by GC/MS. The combination of FTIR, NMR and GC/ MS makes it possible to obtain the multiple profiles of the ethanol-benzene extractives, which is essential for the confident chemical identification of D. odorifera and D. stevensonii.