Combined QTL mapping,GWAS and transcriptomic analysis revealed a candidate gene associated with the timing of spring bud flush in tea plant(Camellia sinensis)

Dear Editor,The timing of the spring bud f lush(TBF)is a crucial agro-nomic trait for the tea plant,as it strongly influences the yield and economic value of harvested fresh tea leaves.The TBF of tea plant is generally defined as the date when>30%of the growing tender shoots have reached the stage of one bud with one to three leaves,referred as to the stage of one and a bud,two and a bud,and three and a bud,respectively.

The continuous wavelet projections algorithm: A practical spectral-feature-mining approach for crop detection

Spectroscopy can be used for detecting crop characteristics. A goal of crop spectrum analysis is to extract effective features from spectral data for establishing a detection model. An ideal spectral feature set should have high sensitivity to target parameters but low information redundancy among features.However, feature-selection methods that satisfy both requirements are lacking. To address this issue,in this study, a novel method, the continuous wavelet projections algorithm(CWPA), was developed,which has advantages of both continuous wavelet analysis(CWA) and the successive projections algorithm(SPA) for generating optimal spectral feature set for crop detection. Three datasets collected for crop stress detection and retrieval of biochemical properties were used to validate the CWPA under both classification and regression scenarios. The CWPA generated a feature set with fewer features yet achieving accuracy comparable to or even higher than those of CWA and SPA. With only two to three features identified by CWPA, an overall accuracy of 98% in classifying tea plant stresses was achieved, and high coefficients of determination were obtained in retrieving corn leaf chlorophyll content(R^(2)= 0.8521)and equivalent water thickness(R^(2)= 0.9508). The mechanism of the CWPA ensures that the novel algorithm discovers the most sensitive features while retaining complementarity among features. Its ability to reduce the data dimension suggests its potential for crop monitoring and phenotyping with hyperspectral data.

Comparative analysis of volatile compounds in different muskmelon cultivars in Xinjiang based on HS-SPME-GC-MS and transcriptomics

Volatile flavor has prompted a great amount of influence in acceptance and view points in fruit products.Melon(Pyrus communis)is an aromadense fruit,thus,the evaluation of volatile flavor is crucial to melon-breeding.The volatile compounds present in nine varieties of Xinjiang muskmelons were identified and analyzed using the headspace solid-phase microextraction and gas chromatography-mass spectrometry methods.In addition,transcriptomics were used to discover the differential genes in fatty acid degradation pathways.It was found that a total of 170 volatile substances,including 52 alcohols,41 esters,24 aldehydes,32 ketones,14 acids and seven phenols,were identified in the nine melons.Results of PCA showed that 3-nonanol,2-nonanol,bis(2-ethylhexyl)adipate,and 2-methylpropanal contributed more to the flavor of melon.It was verified that high activities of acyl-coenzyme A cholesterol acyltransferase(AAT)promoted the conversion of alcohols to esters,so that the melons have a high content of esters.Four genes of long-chain acyl-CoA synthetase were mainly responsible for the large difference in volatile substances.This practice may further undermine the primary rationale for the breeding and promotion in different cultivars of muskmelon.

Effects of dehydration speed on the metabolism of membrane lipids and its relation to the browning of the Thompson seedless grape

Xinjiang is the main producing area of raisins and the largest green raisins production base in China.The browning of Thompson seedless grape raisin is extremely serious during the drying process,and has become the key issue in the development of Xinjiang raisin industry.Previous studies have shown that dehydration speed has a great impact on the browning of Thompson seedless grape,but few relevant mechanisms have been studied.Here,we demonstrate the effect of dehydration speed on lipid metabolism and its relation to the browning of the Thompson seedless grape during drying.Compared to slow dehydration treatment,rapid dehydration treatment of the Thompson seedless grape exhibited a lower degree of browning and activities of lipoxygenase(LOX),a higher index of unsaturated fatty acids and degree of unsaturated fatty acid.Moreover,the Thompson seedless grape treated with rapid dehydration resulted in a lower rate of superoxide anion production,hydrogen peroxide content,membrane permeability,and malondialdehyde content.These findings demonstrate that rapid dehydration inhibiting the browning of Thompson seedless grapes might be due to the inhibiting activities of LOX and the lower accumulation of reactive oxygen species.These activities can inhibit lipid peroxidation and slow the decomposition of unsaturated fatty acid in the membrane in Thompson seedless grapes,protecting the cellular membrane structural integrity,which may result in less contact of polyphenol oxidase with phenolic substrates and less enzymatic browning during drying.The results provide a theoretical basis for the application of rapid dehydration in drying Thompson seedless grapes.