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  • Author or Editor: Juan Zalapa x
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Plant improvement incorporating quantitatively inherited yield component traits is technically difficult, time consuming, and resource demanding. In melon (Cucumis melo L.), the inheritance of yield components is poorly understood. A unique highly branched fractal melon plant type has been developed by the U.S. Department of Agriculture (USDA) from exotic germplasm to improve yield of U.S. Western Shipping type melons (Group Cantalupensis). In order to more effectively develop useful germplasm for commercial use the genetic of components of yield must be clearly understood. Thus, the genetics of branching, an important yield component, was investigated. Melon progeny derived (F1, F2, F3, BC1P1, and BC1P2) derived from a cross between USDA line 846-1 (P1) and Top-Mark (P2) were used to evaluated in two locations (Wisconsin and California) to estimate of components of variance, and narrow-sense (h2N) and broad-sense (h2B) sense heritabilities. Lateral branch numbers among 71 to 119 F3 families were significantly different (P ¾ 0.01) regardless of test environment. Covariance analyses indicates that branching is moderately heritable (h2B = 0.62 to 0.76, h2N = 0.43 to 0.48), and conditioned by several additive factors (perhaps 2 to 4) that are highly additive. Although environment plays an important role in lateral branch development, family rankings over environments were relatively consistent, indicating that effective selection for this trait should be useful for incorporating the fractal plant habit into Western Shipping melon. The significant additive component underlying lateral branch number indicates that quantitative trait loci (QTL) conditioning this yield component might be identified for use in marker-assisted selection.

Free access

Plant reserves play a key role in woody perennial plant winter survival and growth resumption in the spring. In fruit crops, reserves are critical for production in temperate climates when nutrient uptake is minimal and photosynthate production is limited in newly emerged leaves. Fall nitrogen (N) fertilization can be used to increase the availability of plant reserves to support and enhance vegetative growth and fruit production the following growing season. The objective of this study was to test the effect of fall N fertilization on fruit production by evaluating yield components and their relationships to vegetative growth. A split-plot design was established in three ‘HyRed’ cranberry production beds at a farm in central Wisconsin in a 3-year study. Fall N treatments were the main effect and consisted of plots receiving a single application of 0%, 10%, 20%, and 40% of the standard N application (67 kg⋅ha–1) used during the growing season. Summer N fertilization treatments were split in five weekly applications as subplots and consisted of a complete (100%) and a balance (60%, 80%, and 90%) of the standard N application (67 kg⋅ha–1) used during the growing season. Yield was unaffected by either the fall or summer fertilization treatments, but there was an increase in berry weight and a reduction in the number of fruit per unit area using the 40% fall N fertilization treatment. The lower number of fruit per unit area resulted from an increase in the proportion of vegetative uprights—a phenomenon related to an increased length of uprights. Prolonged growth may have affected the flower bud induction window, which occurs in early fall. The fall N fertilization effect of increased vegetative growth may have been the result of an increased availability of N in spring. This result could be advantageous in the establishment of new beds or the recovery of vines that have experienced stress.

Open Access

Informed assessment of priority genetic traits in plant breeding programs is important to improve the efficiency of developing cultivars suited to current climate and industry needs. The efficiency of genetic improvement is critical for perennial crops such as cranberries, as they usually involve more resources, time, and funding compared with other crops. This study investigated the relative importance of cranberry producers’ preferences for breeding traits related to fruit quality, productivity, plant physiology, and resistance to biotic and abiotic stresses. Industry responses revealed that fruit characteristics affecting fruit quality, including firmness, fruit size and anthocyanin content, and resistance to fruit rot, were the most desired traits in new cranberry cultivar release. These traits have the potential to increase the quality standards needed to process high-value sweetened dried cranberry products, positively affecting price premiums received by producers, which is critical for the economic viability of the cranberry industry. Our findings will be useful to breeders and allied scientists seeking to develop an advanced DNA-based selection strategy that would impact the global cranberry industry.

Open Access

Vaccinium meridionale (section Pyxothamnus), a tetraploid species native to higher altitude locations in Jamaica, Colombia, and Venezuela, is of interest to Vaccinium breeders for its profuse, concentrated springtime flowering and monopodial plant structure, both of which may be useful in breeding for mechanical harvest. In this study, tetraploid V. meridionale was hybridized successfully as a male with 4x V. macrocarpon (section Oxycoccos, American cranberry). The first-generation hybrids with 4x cranberry were intermediate in morphology and notably vigorous. The 4x F1 hybrids displayed a vining plant structure, increased flower bud numbers, and white campanulate flowers. The F1 hybrids displayed modest fertility as females upon selfing and backcrossing to 4x V. macrocarpon. Evaluations of male fertility found good pollen production and a range of pollen quality ranging from very good to poor. Hybrids functioned well as males in crosses that used US 1930, a V. meridionale–V. vitis-idaea hybrid as the female. The fertility suggests that these hybrids, despite being derived from intersectional crosses, might be used conventionally in cranberry breeding without significant difficulty.

Open Access