Glucosinolates (GLS) are secondary metabolites commonly occurring in Brassica crops and more than 130 different GLS have been reported in diverse plants. Recent studies have indicated that isothiocyanate (ITC) derived from GLS by hydrolysis had a potential for anticancer activity against several rumor cells on human. In addition, it was found that glucoraphenin (GRE) and glucoraphasatin (GRH) were abundant and differently regulated in radish plant, depending upon organs and developmental stages. Microspores isolated from flower buds of radish were cultured in vitro to obtain doubled haploid (DH; but homozygous) lines in a short time period. The present study was conducted to determine the concentration of GRE and GRH, an immediate precursor of ITC from DH lines of radish plant. Total 41 DH lines were selected based on flow cytometry analysis. The seeds, obtained by bud pollination from the DH lines, were planted and 3-weeks-old young seedlings were used for the major aliphatic GLS analysis. Amounts of GRH were highly variable from the DH lines ranging from 2.3 to 31.5 mg·g-1 dry weight (DW). The donor plant (DP) contained 18.4 mg·g-1 DW. It was noticed that there were 6-fold differences in the amounts of GRE between the highest and lowest DH lines. Among 41 lines tested, 14 DH lines of radish plant were significantly reduced in the amount of sum of GRH and GRE compared those of the donor plant (P<0.05), whereas only three lines increased. The results obtained in the present study will lend to select genotypes with low and high GLS contents of radish plant. In addition, those DH lines will aid to elucidate a biosynthetic pathway of the aliphatic GLS in radish plant, which remain for the most part unsolved.

Investigation of flowing time, flower structure, microspore density, microspore vitality and microspore-derived embryo (MDE) formation rate according to the light quality treatment on broccoli donor plant was accomplished. The material was 08-8-3 line yielding high MDE production rate having 4.0 ± 0.5 mm flower bud length. The donor plant was cultivated with light quality treatment of red LED light, red+blue+white LED light and fluorescent light. The light intensity was 50 μ molm-2s-1 and photoperiod was 16/8 hours (light/dark). The flowering time was fastest at red LED light treatment compared to the other light treatment condition. 100.0, 36.4 and 18.2% of flower bud with longer stigma length than floral leaf which reported high MDE production rate were found under red LED light, Red+Blue+White LED light and fluorescent lights respectively. The microspore density and MDE production rate per single flower bud was highest at Red LED light. Suitable flower bud and high MDE production rate could be achieved in a short period if using LED light to broccoli donor plant cultivation. The above result is thought to be very useful for the development of a new cultivar of broccoli and other many crops including Brassica using haploid breeding technology. This journal was supported by the National Research Foundation

Heat shock pretreatment, dark culture period and washing medium could have marked effects on microspore embryogenesis. A heat shock pretreatment of microspores at 32.5°C for 48 hours gave high production rate of microspore-derived embryo (MDE) when compare to shorter and longer period. The yield of MDE increased significantly when microspore cultured for 15 days at 25℃ in dark condition followed by heat shock pretreatment. MDE were browned and lost vitality when dark treatment period extended longer than 15 days. This is caused by an insufficient oxygen and light for growing embryo which already formed during dark treatment period. The vitality of a microspore isolated from flower bud stored at 4℃ become decreased at the very first day and the vitality of microspore stored at 4℃ in the form of flower bud itself become decreased from the 5th day after storage. This shows the possibility of getting a certain period of storage for a suitable flower bud in MDE formation. The yield of MDE was most effective when isolated microspore was had with MS medium compared to B-5 and NLN medium and also showed most effective result with sucrose 130 g􀂂L-1 in additional sucrose concentration. The above result is thought to be very useful for the development of a new cultivar of radish and other many crops including Brassica using haploid breeding technology.

미생물제제 및 화학비료 시비에 따른 무와 배추의 생육 변화를 조사하기 위해 지상부와 지하부의 길이, 엽면적, 그리고 중량을 측정하였다. 시비 종류에 따른 무의 지하부 생체중은 미생물제제와 화학비료의 혼합 시비에서 148.9g으로 가장 높아 화학비료 처리구(112.8g)와 비교하여 약 1.3배 증가하였으며, 지상부의 생체중 역시 미생물제제와 화학비료의 혼합 시비 처리구(160.3g)에서 화학비료 처리구(111.1g)와 비교해 약 1.4배 증가하였다. 미생물제제와 화학비료를 혼합하여 처리하였을 때 생육이 가장 왕성하였으나 미생물제제 처리구도 화학비료 단독시비 처리구의 생육과 비교하여 지상부, 지하부 모두 생체중이 증가하는 것을 확인할 수 있었다. 배추의 지상부 생체중은 미생물제제와 화학비료의 혼합시비 처리구에서 316.6g으로 가장 높아 화학비료 처리구(225.7g)와 비교하여 1.4배 증가하였으며, 또한 지하부의 생체중도 미생물제제와 화학비료의 혼합시비 처리구(4.4g)에서 화학비료 처리구(3.1g)와 비교하여 1.4배 증가하였다. 배추의 엽면적은 미생물제제와 화학비료의 혼합시비 처리구, 화학비료 처리구, 미생물제제 처리구에서 각각 3567.7, 2387.5, 2735.9cm2로 미생물제제의 처리로 배추의 엽면적이 증가함을 확인할 수 있었다. 실험의 결과를 통해 미생물제제가 관행의 농법에서 사용되는 화학비료를 대체하여 친환경비료로 사용될 수 있을 것으로 판단된다. 또한 화학비료에 토양미생물제제를 혼용 처리하여 무와 배추의 생육을 크게 향상시킬 수 있을 뿐 아니라 건전한 육종재료를 육성하기 위한 시비 방법으로 이용될 수 있을 것으로 판단된다.