본 연구는 폴리에틸렌 중합에 이용되는 Ziegler-Natta 촉매와는 다른 Indene및 Cyclopent adien을 기반으로 하는 다양한 메탈로센 촉매를 사용하여 폴리에틸렌 왁스를 중합하고 중합한 폴리에틸렌 왁스 의 특성에 대해 분석하고 평가하였다. 폴리에틸렌 왁스 중합은 각 다른 구조의 리간드를 포함하는 메탈로 센 촉매에 대하여 중합온도, 연쇄이동제로 사용되는 수소와 에틸렌가스의 비율을 조정하여 다양한 조건하에서 중합을 시도 하였으며 그에 따른 분자량과 분자량 분포, 촉매 수율을 비교 분석하였다. 결과적으로 본 연구를 통하여 저분자량을 가지며 좁은 분자량 분포를 가지기에 적합한 메탈로센 촉매의 구조를 제안하였으며 이상적인 폴리에틸렌 왁스를 중합 할 수 있었다.

Root-knot nematode, Meloidogyne incognita is a virulent pest of solanaceaous crops worldwide. The M. incognita resistance gene Me7 derived from Capsicum annuum CM334, is located on chromosome 9. In the present study, an F2 population derived from a cross between ECW03R and CM334 was used to locate the Me7 gene. An F2 population was inoculated using approximately 1,000 second-stage juveniles per individual plant. Phenotype screening was done 45 days after inoculation by using gall index system. The phenotype study of 503 F2 individual showed 391 resistant and 112 susceptible plants. The 3:1 phenotypic ratio confirmed that resistance phenotype is controlled by a single dominant gene. Previously reported two markers were tested to reveal the linkage of markers to phenotype. Two markers, CAPS_F4R4 and SCAR_PM6a were located at 4.3 and 2.7 cM from the resistance gene, respectively. Additional SNP markers were developed using CM334 reference genome information to narrow down the position of the gene, but no closer markers could be developed due to errors of DNA sequence assembly. The closest marker was positioned on telomere of the chromosome 9 long arm, where tens of other NB-LRR genes are clustered. NB-LRR genes are being used as candidates to identify the Me7 gene.

Capsicum diversity is getting lower in modern crops because of the genetic erosion. In Capsicum, breeders have been mainly focused on agriculturally important traits such as disease resistances, high yield and pungency. This narrow breeding pool hampered to develop improved cultivars. It has become a hot issue to conservation of genetic diversity and exploitation of wild germplasm in Capsicum. However, although a large number of accessions are maintained in Capsicum germplasm collections, their use for crop improvement is limited by the scarcity of information on genetic diversity, population structure and proper phenotypic assessment. The identification of representative and manageable subset of accessions would facilitate access to the diversity available in large collections. A genome wide germplasm characterization using molecular markers can offer reliable tools for adjusting the quality and representativeness of core samples. We investigated patterns of molecular diversity at 48 single nucleotide polymorphisms (SNPs) in 4056 accessions from 11 Capsicum species from 89 different countries. Using these genetic variations and 32 different morphological traits, 250 core set was selected in whole Capsicum germplasm. The core collection could be a primary source for distributing germplasm to pepper breeders and other national programs as well as for evaluation