Evaluations and Correlated Responses for Resistance to Chloramben Herbicide in Cucumber

Abstract

<jats:p>The U.S. cucumber germplasm collection (753 accessions) and U.S. adapted processing cucumber <jats:italic>(Cucumis sativus</jats:italic> L.) inbreds and hybrids were surveyed for response to 6.7 kg ae/ha of chloramben. Nine plant introductions (PI 165952, 173892, 179676, 275411, 277741, 279464, 279465, 436609, and 482464) were classified as tolerant to chloramben, based on percentage and rate of field emergence and seedling vigor. All adapted strains evaluated were susceptible to chloramben injury. The chloramben-tolerant accessions (C<jats:sub>0</jats:sub>) were subjected to two cycles of recurrent half-sib family selection that resulted in 11 C<jats:sub>2</jats:sub> families. These families, a susceptible adapted line (WI 2870), and the resistant PI 436609 were evaluated in the field (6.7 kg ae/ha) and laboratory (0.0, 0.01, and 0.0001 M) for response to chloramben challenge. Significant <jats:italic>(P</jats:italic> = 0.05) differences between families were observed for percentage emergence and phytotoxicity ratings. Correlations between emergence and phytotoxicity ratings at two dates were low <jats:italic>(r<jats:sup>2</jats:sup></jats:italic> = -0.32 and – 0.05). Significant <jats:italic>(P =</jats:italic> 0.05) interfamily differences were also recorded for percentage germination, hypocotyl length, primary root length, and number of lateral roots in the laboratory. Correlated responses between these growth variables were high <jats:italic>(r<jats:sup>2</jats:sup></jats:italic> = 0.78 to 0.84), but correlations between field and laboratory observations were low <jats:italic>(r<jats:sup>2</jats:sup></jats:italic> = -0.31 to 0.24). We hypothesize that the genetic response to chloramben challenge under laboratory conditions depends on the concentration of the chemical administered. Chemical name used: 3-amino-2, 5-dichlorobenzoic acid (chloramben).</jats:p>

Toxicity of Ethylene Glycol Vapors to Cucumbers

“…Nonetheless, the rooms and chambers have been fitted with filters to prevent any possible injury. Cucumbers are one of the most sensitive plants to air pollutants and to herbicides (Pezet and Gindrat, 1978;Staub and Knerr, 1991). Thus, the effects of ethylene glycol vapors on other plants may be more subtle, causing no obvious symptoms of injury, but possibly only a general stunting.…”

Ten Cycles of Recurrent Selection for Fruit Yield, Earliness, and Quality in Three Slicing Cucumber Populations

“…Recurrent selection has been used in cucumber to increase low temperature germination ability (Nienhuis et al, 1983;Staub et al, 1988), herbicide resistance (Staub et al, 1991), and disease resistance (Sloane et al, 1985). Recurrent selection methods such as S 1 line, half-sib family and full-sib family selection have been effective for yield improvement in cucumber Lower, 1983, 1984;Nienhuis, 1982;Nienhuis and Lower, 1988;Wehner, 1989).…”