Heat treatment has been widely used to control some stored insect pests. The Indian meal moth, Plodia interpunctella, gives massive economic loss to most stored grains. Heat tolerance of P. interpunctella was assessed in most developmental stages in this study. Heat treatment at 44oC for 1 h was lethal to P. interpunctella. Compared to other developmental stages, late larval instar larvae were more tolerant to the heat treatment. Some of the fifth instar larvae could survive under 44oC for 80 min, but completely died at exposure to 45oC for 80 min. However, the survival rates of the larvae significantly increased by pre-exposure to sublethal temperature at 37oC. The rapid induction of heat tolerance was accompanied with increases in gene expressions of two heat shock proteins, Hsp70 and Hsp90, but not in that of Hsp25. Interestingly, hemolymph trehalose levels also increased from 39.2 mM to 51.3 mM by pre-exposure to 37oC for 30 min. These results suggest that P. interpunctella induces a rapid heat tolerance by up-regulation of heat shock protein levels and hemolymph trehalose levels.

밀양 23호/기호벼 유래 164 RILs(F17)을 이용하여, 종자의 휴면과 관련이 있는 수발아 저항성, 건열 저항성 및 종자수명을 검정하고, 이들 상호간 상관관계를 조사하였다. 출수 40일째에 밀양23호와 기호벼의 수발아율은 0%, 7%이었고, M/G RILs은 0~50.9%의 범위를 보였으며, 평균 3.2%였다. 90℃, 24시간 건열처리후 밀양23호와 기호벼는 99.2%, 37.6%의 발아율을 보였고, T50은 2.7일, 12.9일로 유의한 차이를 보였으며, M/G RILs의 평균 발아율은 72.4%였다. 상온저장 한 종자수명은 밀양23호는 수확후 3.5년까지도 80% 이상의 종자 발아율을 유지하였으나, 기호벼는 18개월 후부터 급격히 발아력이 감소하여(30%이하), 42개월 후 발아력을 완전히 상실하였다. M/G RILs의 종자활력은 수확후 42개월까지 71계통이 90%이상의 발아율을 보였다. 수발아 저항성, 건열 저항성 및 종자수명은 밀양 23호와 기호벼 간에 뚜렷한 품종간 차이를 보였으며, M/G RILs은 양친의 중간값에 가까운 평균값을 보였다. 건열저항성과 종자수명 간에는 고도로 유의한 정의 상관관계를 보였고, 수발아와 종자수명, 수발아와 건열저항성 간에는 부의 상관관계가 성립하였다.

This study as a part of an extensive green roof system development was carried out to assess the heat tolerance of 11 species Sedum spp. on the extensive green roof system: S. kamtschaticum, S. oryzifolium, S. polystichoides, S. sarmentosum, S. acre, S. album, S. reflexum, S. rupestre, S. sexangulare, S. spurium, and S. telephium. Electrolyte leakage evaluation was used to estimate the heat tolerance level of each Sedum at 40°C, 45°C, 47.5°C, 50°C, 52.5°C, 55°C, and 57.5°C. The critical temperatures at the midpoints of sigmoidal curves fitted through electrolyte leakage (EL) were predicted with the range of 54.0°C to 65.2°C. S. album, S. telephium, and S. sexangulare were more tolerant of high temperature than the others. In field condition, the heat tolerance of 11 species Sedum spp. applied to the suggested extensive green roof system was also estimated by EL evaluation. The EL (%) values of 11 species Sedum spp. subjected to maximum temperature (46.7°C) recorded during the experimental periods were lower than 50% except S. kamtschaticum and S. spurium. Especially, S. album, S. rupestre, and S. telephium were ranked higher than the others in heat tolerance. The most Sedum spp. would show good heat tolerance on the extensive green roof system if the maximum temperature on rooftop was below 50°C in summer season.

High temperature is one of major environmental stress. Heat tolerance managing is difficult through the phenotypic selection, so marker assistant selection (MAS) using molecular markers like as RAPD, SSR etc. was tried to select useful traits for heat tolerance. Fourteen SSR markers reported by previous research were selected for this research. We tried to evaluate 14 SSR markers for MAS using 31 useful wheat resources including 24 crossing line from Turkey, six Korean wheat cultivars and Chinese spring. The average of the number of alleles and PIC values in this study were 6.14 and 0.64, respectively. Two major clades and four sub clades were grouped by phylogenetic tree using UPGMA. Four Korean wheat cultivars were distinct from other Turkey resources in the phylogenetic dendrogram. From the results, we expected that these markers were able to adapt to screening wheat genotyping for heat tolerance.

High temperature is one of major environmental stress. Some of molecular markers related heat stress or tolerance have been reported by many researchers. Heat tolerance managing is difficult through the phenotypic selection, so marker assistant selection (MAS) using molecular markers like as RAPD, SSR ect. was tried to selection of useful traits for heat tolerance. Fourteen SSR markers reported by previous research were selected for this research. These markers were linked to important traits including grain filling duration, HIS (Heat susceptibility index) grain filling duration. In this study, we tried to evaluate 14 SSR markers for MAS using 31 useful wheat resources including 24 crossing line from Turkey and six Korean wheat cultivars using 14 SSR markers. The average of the number of alleles and PIC values in this study were 6.14 and 0.63, respectively. Two major clades and six sub clades were grouped by phylogenetic tree using UPGMA program. Six Korean wheat cultivars were distinct from other Turkey resources in the phylogenetic dendrogram. From the results, we expected that these markers were able to adapt to screening wheat genotyping for heat tolerance.

To obtain a better insight into a possible common regulatory mechanism shared in response to heat and cold stresses in model monocot plant, expression profiling for several selected transcripts of rice (O. sativa L.) was examined from meiotic stage panicle samples of a number of different cultivars including both heat/cold tolerant and susceptible varieties. Induction of several of these genes in response to heat stress treatment was observed across all different rice varieties tested, but no differential induction kinetics between the heat-tolerant and susceptible varieties was discernable for these genes. On the other hand, a few genes that are known to be involved in ROS signaling showed different induction kinetics between the tolerant and susceptible varieties, suggesting that these genes might be playing a key role in conferring the heat/cold stress tolerance at reproductive stage of tolerant rice varieties. This approach was also augmented by comparative gene expression data analyses, utilizing expression data of other monocots and dicots model plants available in the database. Based upon these results, a preliminary gene pyramiding effort to estimate contributing factor of several selected alleles after putting these genes together is underway. This work was supported by a grant from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center No.PJ009076), Rural Development Administration, Republic of Korea.