Author
HANCOCK, J - MICHIGAN STATE UNIV | |
HOKANSON, S - USDA-ARS BELTSVILLE | |
Finn, Chad | |
HUMMER, K - USDA-ARS-NCGR -CORVALLIS |
Submitted to: Acta horticulturae
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/20/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Over 20 explorations have been undertaken in the last two decades to collect native octoploid strawberry (Fragaria sp) germplasm from North and South America. These are the species from which the commercial strawberry was developed. We selected a "supercore" of 38 genotypes from this material that encompasses a wide range of horticultural and climatic attributes, and have analyzed their performance at five locations in the USA (Md., Minn., Mich., Penn., Ore.) The supercore was selected from most of the major climatic zones in North and South America where strawberries are found. Plants were planted on non-fumigated ground and were trained into wide matted rows. Plant vigor, flower number per inflorescence and runner density were rated at all locations during bloom. Winter survival was assessed in Michigan. When about 30% of the fruit were ripe in each plot at all locations, fruit set, appearance, weight, firmness and flavor were estimated, along with skin and flesh color. Each genotype's development was followed through the season, and those flowering in the spring and summer were considered day-neutral. Plots were rated for the prevalence of leaf diseases in the fall. Four genotypes were identified as the best widely-adapted, short-day genotypes; two as the best broadly-adapted, day-neutral clones and three for their performance at individual sites. These genotypes are being further used to enhance breeding material. Technical Abstract: Over 20 explorations have been undertaken in the last two decades to collect native octoploid strawberry (Fragaria sp) germplasm from North and South America. We have selected a "supercore" of 38 genotypes that encompasses a wide range of horticultural and climatic attributes, and have analyzed their performance at five locations in the USA (Hancock et al., 2000). The supercore was selected from most of the major climatic zones in North and South America where strawberries are found. Representatives of all the subspecies within F. chiloensis and F. virginiana were incorporated, along with cultivated and non-cultivated forms of F. chiloensis from South America. At each location (Md., Minn., Mich., Penn., Ore.), the genotypes were planted in a randomized complete block design,with 2-4 plants per block at 40 cm spacing within rows and 30 cm spacing between rows. Plant vigor, flower number per inflorescence and runner density were rated at all locations during bloom. Winter survival was assessed in Michigan. When about 30% of the fruit were ripe in each plot at all locations, fruit set, appearance, weight, firmness and flavor were estimated, along with skin and flesh color. Each genotype's development was followed through the season, and those flowering in the spring and summer were considered day-neutral. Plots were subjectively rated for the prevalence of leaf diseases in the fall. Four genotypes were identified as the best widely-adapted, short-day genotypes; two as the best broadly-adapted, day-neutral clones and three for their performance at individual sites. |