Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

Abstract
Introduction
Materials and Methods
    Plant materials
    Lesion development assay using leaves of B. rapa andinoculation of B. cinerea isolates
    Measuring days to flowering and plant height
    Counting numbers of aphids and thrips
    Statistical analysis
Results and Discussion
    Parental lines and RIL population behaves differentlyagainst five B. cinerea isolates
    Response to insects: Aphids and thrips
    Vegetative growth estimated by measuring days toflowering and plant height
    Comparative analysis among various phenotypic traits
References

• Soon-Tae Kwon(Department of Horticulture and Breeding, Andong National University) Corresponding author
• Inhwa Yeam(Department of Horticulture and Breeding, Andong National University)
• Jong Hwa Shin(Department of Horticulture and Breeding, Andong National University)