Mapping of Purple Gene in Spears of Asparagus(Asparagus officinalis L.)

[Objectives]This study was conducted to find out regulatory genes related to purple in spears of asparagus(Asparagus officinalis L.).[Methods]The stable asparagus inbred line JX1513-5(the base of the spear is purple)and JLV1718-7(the base of the spear is green)were used as parents to study the genetic law of purple/green traits in their offspring.[Results]The results showed that the purple in the basal part of asparagus spear was controlled by a pair of alleles,and purple was dominant over green.The F 2 segregation population was resequenced by the bulk segregation analysis(BSA)method,and the purple trait in the basal part of asparagus spear was located in the interval of 24.51-25.08 Mb on Chr07 chromosome,which included 47 genes.According to the annotation information,three candidate genes were screened out:LOC109849403,LOC109849430 and LOC109849442.The candidate genes were verified by real-time fluorescence quantitative PCR(qRT-PCR),and finally LOC109849442 was obtained as the candidate gene for controlling the purple/green trait in the basal part of asparagus spear.[Conclusions]This study lays a foundation for the breeding of new asparagus varieties and molecular marker-assisted breeding.

Effects of Salt Stress on Growth and Ion Distribution in Seedlings of Asparagus officinalis L.

An Asparagus officinalis L. cultivar NJ978 was used to study the growing rate,salt ion content and mineral ion uptake and distribution in plants under salt stress. The results showed that salt stress significantly inhibited seedling growth and there was a negative relationship between seedling growth and salt concentration. The seedlings growth showed no significant decrease under low salt stress( NaCl≤50 mmol/L),while high concentrations of NaCl led to detrimental effects on the growth of A. officinalis L.. With the increase of NaCl concentration,the Na+content increased gradually in A. officinalis L. roots,stems and leaves while the K+and Ca^(2+) contents had slow decreases. Under low salt stress,the seedlings of A. officinalis L. could prevent Na+from transporting to aerial part by withholding Na+in root,which could keep the balance of ions in aerial part,but under high salt stress( NaCl > 100 mmol/L),the aerial part of seedlings accumulated superabundance of Na+,which limited the uptake of K^+and Ca^(2+),so seedlings were damaged heavily,which manifested as the gradual decrease of K^+/Na+and Ca^(2+)/Na+in the roots and aerial part of the seedlings. The selective absorption of K^+,Ca^(2+)and Na^+( ASK,Naand ASCa,Na) was significantly increased with increased salinity,while the selective transportation( TSK,Naand TSCa,Na) increased at first and then decreased with the increased salinity. Therefore,the strong ability of salt exclusion and the regionalized distribution of ions in roots,stems and leaves could be one of the salt tolerance mechanisms of A. officinalis L.

A Preliminary Study on the Regularity of Outbreak of Thrips in Asparagus-bean Interplanting Fields

[Objectives]This study was conducted to clarify the composition and occurrence regularity of thrips in asparagus-soybean intercropping fields.[Methods]The species and occurrence dynamics of thrips in asparagus-bean intercropping fields in Luquan District of Shijiazhuang were investigated.[Results]There were 7 species of thrips in this area,namely,tobacco thrips[Thrips alliorum(Priesner)],western flower thrips[Frankliniella occidentalis(Pergande)],Scolothrips takahashii Priesner,Megalurothrips usitatus(Bagrall),Sussericothrips melilotus Han and Aeolothrips fasciatus.As the dominant species,tobacco thrips had two peak outbreaks in late June and late September,and maintained a high quantity level for a long time.Other thrips had fewer population and different occurrence time,but were greatly affected by temperature,humidity and host crop species.[Conclusions]This study provides a theoretical basis for the forecast and comprehensive control of thrips in North China.

Rapid Determination of Seed Number and Thousand Kernel Weight of Asparagus officinalis L.Using Image Processing Method

Asparagus officinalis L.is favored by its high health function,but its hybrid seeds are expensive.The amount of seed,seed plumpness and germination rate are related to the production costs of breeding enterprises and large growers.Therefore,it is necessary to investigate the seed number and thousand kernel weight of A.officinalis L.This study developed a quick and accurate method to measure the seed number and thousand kernel weight of A.officinalis L.using image processing technology.Seed sample of A.officinalis L.was scanned with 200 dpi resolution,and the seed number was then obtained using Image-ProPlus software.After weighing the seeds,thousand kernel weight was finally calculated.By recording‘macro’,the batch processing of the samples can also be realized.This method is simple and accurate,and can greatly save the time of investigation.