KOREASCHOLAR

Calla lily is a mainstream floricultural crop but itscommercial success is limited by severe susceptibility to softrot. This disease can be controlled to some extent by imple-menting appropriate cultural practices but developing resis-tant cultivars against this pathogen is the most promisinglong-term strategy. The purpose of this work was to developnew cultivars resistant to this bacterial disease by initiatingan appropriate breeding programme. Field observations of120 resistant lines selected by a leaf-disk susceptibility testwere carried out and survival rates were measured. Twolines were selected after further evaluation of resistancelevel, flowering characteristics and following guidelines forconduct of tests for distinctness, homogeneity, and stability.Further preference testing of the selected lines by growers,consumers, researchers and agricultural advisors was car-ried out with excellent results. The selected new lines are‘Silky White’ and ‘Mont Blanc’ which emerge as the first,soft-rot resistant calla lily cultivars from our breeding program.

Abstract
 Introduction
 Materials and Methods
  Plant material
  Bacterial strain
  Leaf disk test (LDT)
  Statistical analysis
 Results
  Selection of resistance line for crossing
  Hybrid selection by LDT
  Field selection
 Discussion
 References

• Hae Ryong Cho(National Institute of Horticultural & Herbal Science, Rural Development Administration)
• Ki Sun Kim(Department of Plant Science, Seoul National University)
• Hyang Young Joung(National Institute of Horticultural & Herbal Science, Rural Development Administration)
• Ki-Byung Lim(Department of Horticultural Science, Kyungpook National University) Corresponding author