THE RELATIONSHIP BETWEEN POWDERY MILDEW (SPHAEROTHECA-FULIGINEA) RESISTANCE AND LEAF CHLOROSIS SENSITIVITY IN CUCUMBER (CUCUMIS-SATIVUS) STUDIED IN SINGLE SEED DESCENT LINES
S. Zijlstra et al., THE RELATIONSHIP BETWEEN POWDERY MILDEW (SPHAEROTHECA-FULIGINEA) RESISTANCE AND LEAF CHLOROSIS SENSITIVITY IN CUCUMBER (CUCUMIS-SATIVUS) STUDIED IN SINGLE SEED DESCENT LINES, Euphytica, 81(2), 1995, pp. 193-198
The genetic relation between powdery mildew resistance and sensitivity
for leaf chlorosis of glasshouse cucumber was investigated. The powde
ry mildew resistant, leaf chlorosis sensitive hybrid variety 'Profito'
was crossed with the powdery mildew susceptible, non chlorosis sensit
ive hybrid variety 'Corona'. Forty four F-6 inbred lines of this cross
, produced by single seed descent, were tested for powdery mildew resi
stance (PMR) and leaf chlorosis sensitivity (LCS). PMR and LCS were po
sitively correlated (r = 0.59). One or more of the PMR genes probably
causes LCS as a pleiotropic effect or is closely linked to LCS, but al
so other factors, not genetically linked to PMR can cause LCS. Five F-
6 lines combined a significantly higher level of PMR than 'Corona' wit
h a significantly lower LCS than 'Profito'. Three of these lines could
hardly be distinguished from 'Corona' for the level of LCS.