Pola Pewarisan Sifat Ketahanan Terhadap TYLCKaV Pada Tanaman Cabai (Capsicum annuum L.)

Fatimah Azzahra, Prof. Dr. Rudi Hari Murti, S.P., M.P.; Dr. Elly Syafriani, S.P

2026 | Tesis | S2 Ilmu Pemuliaan Tanaman

Chili pepper (Capsicum annuum L.) is an economically important horticultural crop in Indonesia, often constrained by the Tomato Yellow Leaf Curl Kanchanaburi virus (TYLCKaV), a Begomovirus transmitted by a whitefly (Bemisia tabaci). This study aimed to analyse the inheritance of resistance to TYLCKaV in chili using segregating populations (F2 and backcross) derived from crosses between resistant (P1) and susceptible (P2) lines. A total of 820 plants from P1, P2, F1, reciprocal F1, F2, BC1P1, and BC1P2 populations were evaluated for disease incidence and severity under controlled inoculation. Resistance was assessed using a five-scale severity scoring system. Results showed that P1 and BC1P1 were highly resistant (0% disease severity), whereas P2 and BC1P2 were susceptible to moderate. F1 and reciprocal F1 populations exhibited partial dominance, with moderate susceptibility. Segregation analysis in F2 (3:1) and backcross populations (BC1P1: 1:0). BC Variance component analysis revealed high additive genetic effects, broad-sense heritability (H2 = 0.83) and narrow-sense heritability (h2 = 0.52), suggesting effective early-generation selection. Castle-Wright estimation predicted 1.3 major genes contributing to resistance. This study demonstrates that TYLCKaV resistance in chili is predominantly monogenic and controlled by dominant genes, providing valuable parental material for breeding programs. Resistant genotypes, particularly P1, can be utilized to develop TYLCKaV-resistant chili cultivars, supporting sustainable production in virus-prone regions.

Chili pepper (Capsicum annuum L.) is an economically important horticultural crop in Indonesia, often constrained by the Tomato Yellow Leaf Curl Kanchanaburi virus (TYLCKaV), a Begomovirus transmitted by a whitefly (Bemisia tabaci). This study aimed to analyse the inheritance of resistance to TYLCKaV in chili using segregating populations (F2 and backcross) derived from crosses between resistant (P1) and susceptible (P2) lines. A total of 820 plants from P1, P2, F1, reciprocal F1, F2, BC1P1, and BC1P2 populations were evaluated for disease incidence and severity under controlled inoculation. Resistance was assessed using a five-scale severity scoring system. Results showed that P1 and BC1P1 were highly resistant (0% disease severity), whereas P2 and BC1P2 were susceptible to moderate. F1 and reciprocal F1 populations exhibited partial dominance, with moderate susceptibility. Segregation analysis in F2 (3:1) and backcross populations (BC1P1: 1:0). BC Variance component analysis revealed high additive genetic effects, broad-sense heritability (H2 = 0.83) and narrow-sense heritability (h2 = 0.52), suggesting effective early-generation selection. Castle-Wright estimation predicted 1.3 major genes contributing to resistance. This study demonstrates that TYLCKaV resistance in chili is predominantly monogenic and controlled by dominant genes, providing valuable parental material for breeding programs. Resistant genotypes, particularly P1, can be utilized to develop TYLCKaV-resistant chili cultivars, supporting sustainable production in virus-prone regions.

Kata Kunci : additive effect, backcross population, disease resistance, heritability, monogenic trait