This is the second of two related reports dealing with the effects of cultivar × environment interactions on cabbage (Brassica oleracea L., Capitata Group) crop traits. This study examined planting date and cultivar effects on physical head traits of processing cabbage and compared these findings to those from a similar study of fresh market cabbage. Six cultivars of processing cabbage were planted in May and June-July of 1999 and 2000 at the OARDC Vegetable Crops Research Branch in Fremont, Ohio. Marketable yield for each crop was determined, and measurements were taken of head weight, diameter, density, and volume, and core length, base width, and volume on more than 450 individual heads. Head and core volume and head density were calculated from these direct measures. Year, planting date, and cultivar significantly affected the majority of head traits. May planting led to higher marketable yield and heavier heads with larger diameters than June-July planting. The most variable trait across cultivars was head volume, which was affected by planting date in all cultivars. Differences between processing and fresh market cabbage were found. Average head polar/equatorial diameter values were affected by planting date in the fresh market but not the processing study. In contrast, head density and core volume as a percent of head volume were affected by planting date in the processing but not the fresh market study.
Annette Wszelaki and Matthew D. Kleinhenz
Nancy J. Zimmerman and Nancy A. Reichert
Seed and seedling cotyledon explants from 14 cultivars were placed on 2 media types to induce organogenesis and somatic embryogenesis. Shoots or somatic embryos were counted to determine effects of cultivar, explant and regeneration type on overall regeneration success. Opposite explant preferences were observed for each regeneration type. In somatic embryogenesis, greater numbers of seedling cotyledons were able to respond, while in organogenesis, seed cotyledons responded in greatest numbers. However, within each cultivar, no explant preferences were observed (except in `Picklebush'). Four cultivars displayed a preference for the somatic embryogenesis regeneration protocol over organogenesis: `Burpee Hybrid II' and `Burpless F1 Hybrid' (fresh market types), and `Cross Country' and `Picklebush' (pickling types). The best individual regeneration rates were obtained with `Cross Country' and `Picklebush' - both for somatic embryogenesis.
James Nienhuis, Joao B. dos Santos, Paul Skroch, and Jan Tivang
Genetic distance was calculated among 92 tomato, Lycopersicon esculentum, genotypes, which included open pollinated cultivars and commercial hybrids of both fresh market and processing types. Over 800 were screened, and 44 10-mer primers which had clear banding patterns and were polymorphic among cultivars were selected. From each of the primers an average of five polymorphic bands were classified for their presence or absence for each genotype. Genetic distance was calculated as the ratio of discordant to total bands scored. A multidimensional scaling (MDS) plot indicated that the processing cultivars, `UC82' derivatives and fresh market types generally formed separate clusters. Within groups, genetic distance corresponded to known pedigree relationships. The genetic distance between duplicate samples of 10 genotypes ranged from 0.01 to 0.05. The results of this study indicated that RAPDs provide a high degree of resolution for estimating genetic relationships among tomato cultivars.
Matthew D. Kleinhenz and Annette Wszelaki
Yield and relationships among head traits were recorded in order to better understand the effects of planting date and cultivar selection on crop quality characteristics and to help increase the efficiency of cultivar development, evaluation, and selection. A total of seven cultivars of fresh market-type cabbage (Brassica oleracea L., Capitata Group) were planted in May and June of 1999 and 2000 at the OARDC Vegetable Crops Research Branch in Fremont, Ohio. Total and marketable yield, head traits (e.g., size, weight, density), and core dimensions were recorded at harvest. Main effects of year (Y), planting date (PD), and cultivar (C) and the Y × C interaction significantly affected seven to 10 of 10 head and core traits. However, the PD × C interaction was significant for head density, the ratio of head polar and equatorial diameter, and core base width. The Y × PD interaction was significant for six of 10 head and core traits. May planting tended to result in greater yield and larger, heavier heads with greater polar/equatorial diameter values relative to June planting. However, head density was unaffected by planting date. The number of head and core traits affected by planting date differed among cultivars. For example, six of 10 head and core traits were significantly affected by planting date in `Cheers' and `DPSX315' while one trait was affected by planting date in `SuperElite Hybrid'. The weight of numerous, individual, market-ready, trimmed heads showed a strong (avg. R 2 value = 0.92) quadratic relationship to average head diameter. These data suggest that large-scale germplasm evaluations may benefit by including multiple plantings, as head weight, volume, diameter, and shape were affected by planting date, possibly due to variation in temperature and rainfall patterns. The data also suggest that routine measurement of numerous head traits in the same evaluations may be unnecessary, as selected traits (e.g., diameter and weight, head volume, and core volume) were strongly related.
Jack E. Staub and Isabelle Y. Delannay
Beit Alpha cucumber ( Cucumis sativus L.) is a Mediterranean fresh-market or processed type that originated in Israel for use in open-field and protected production ( Shaw et al., 2000 ; Villalta et al., 2003 ). This market type develops
Jack E. Staub and Isabelle Y. Delannay
classes ( Staub et al., 2008 ). The European Long market-type cucumber is grown for the fresh market in protected-culture environments (primarily glasshouse and plastic “hoop houses”). Harvestable fruit are 32 to 40 cm in length, smooth, dark green, fine
Ryan J. Hayes, Karunakaran Maruthachalam, Gary E. Vallad, Steven J. Klosterman, and Krishna V. Subbarao
is particularly destructive on lettuce, and all market types are susceptible. Plants often remain symptomless until they near harvest maturity, at which time the symptoms develop quickly. Host resistance is the best long-term control method in lettuce
Jack E. Staub, Isabelle Y. Delannay, and Jin-Feng Chen
.-derived U.S. processing market-type inbred backcross lines (IBL) were released in Jan. 2011 by the Agricultural Research Service, U.S. Department of Agriculture to provide genetic stocks for broadening the genetic base of pickling cucumber. The IBL were
Jack E. Staub, Philipp W. Simon, and Hugo E. Cuevas
-10 is the result of selection in the EOM 402 population that was derived from crossing a U.S. pickling market type [moderately warty, no endocarp/mesocarp pigment, fruit length:diameter (L:D) = 2.8:1.0 to 3.4:1] with Chinese type XIS (extremely warty
Jack E. Staub, James D. McCreight, and Juan E. Zalapa
var. inodorus . Breeding line SC#6 was an S 5 from a complex cross of Eastern U.S. market-type melons ( C. melo var. reticulatus ) selected by Perry E. Nugent (retired, USDA-ARS, U.S. Vegetable Laboratory, Charleston, SC) for germinability at low