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This study was conducted to evaluate the yield performance for University of California (UC) cultivars 'Albion' and 'San Andreas' during summer and fall fruiting season in the northeastern highlands of Korea at 750 meters elevation. We investigated the effects of cultivar, planting date and planting material on fruit productivity in a bench-top peat substrate system. For both cultivars, we compared the yield performance of frozen (-2.2 ) bare-root plants (FBR), potted frozen bare-root plants (PFBR), and potted fresh plants (PF) on four dates: 30 Apr., 15 May, 30 May, and 15 Jun., 2010. Fruit harvest commenced in early June and terminated on 2 Dec. For each cultivar and type of planting material, fruit were harvested twice a week and fruit weight and numbers of marketable and non-marketable fruits were determined for each harvest. Both cultivars performed well in summer and autumn production in high land, although marketable fruit yield for 'San Andreas' was significantly greater than that of 'Albion'. Plants planted on 30 Apr. produced the earliest fruit and the greatest marketable yields, 521.0 and 487.0 g/plant, 24.1 and 23.3 ton/hectare for 'Albion' PFBR and FBR plants, respectively, and 618.3 and 529.6 g/plant, 28.6 and 24.5 ton/hectare for 'San Andreas' PFBR and FBR plants, respectively. Generally, PFBR had higher marketable fruit yield than FBR and PF had the lowest. PFBR is recommended especially for late planting and FBR is acceptable for early planting, while PF is not suitable for this production system. The relationship of fruit productivity and vegetative growth was significantly correlated.Additional key words: day-neutral cultivar, Fragaria × ananassa, summer and autumn production, vegetative growth Hort. Environ. Biotechnol. 52(6):567-575. 2011.

Plant mitochondrial DNA has been described as evolving rapidly in structure but slowly in sequence. However, many of the noncoding portions of plant mitogenomes are not homologous among species, raising questions about the rate and spectrum of mutations in noncoding regions. Recent studies have suggested that the lack of homology in noncoding regions could be due to increased sequence divergence.We compared 30 kb of coding and 200 kb of noncoding DNA from 13 sequenced Fragaria mitogenomes, followed by analysis of the rate of sequence divergence, microinversion events and structural variations.Substitution rates in synonymous sites and nongenic sites are nearly identical, suggesting that the genome-wide point mutation rate is generally consistent. A surprisingly high number of large multinucleotide substitutions were detected in Fragaria mitogenomes, which may have resulted from microinversion events and could affect phylogenetic signal and local rate estimates. Fragaria mitogenomes preferentially accumulate deletions relative to insertions and substantial genomic arrangements, whereas mutation rates could positively associate with these sequence and structural changes among species.Together, these observations suggest that plant mitogenomes exhibit low point mutations genome-wide but exceptionally high structural variations, and our results favour a gain-andloss model for the rapid loss of homology among plant mitogenomes.

Short-day (SD) strawberry cultivars were grown in 2008 and 2009 fall each year to evaluate effects of short-day (SD) treatment on flowering and fall fruit production in the high elevation of South Korea. In 2008, daughter plants of six cultivars 'Maehyang', 'Seolhyang', 'Keumhyang' (Korean short-day cultivars), 'Akihime', 'Red pearl', and 'Sachinoka' (Japanese short-day cultivars) were exposed to short-day (10-h photoperiods) conditions at the high elevation (HE, 800 m elevation) for 35 days beginning in late June. On 31 July, plants were removed from the SD environment and established in a substrate system at the highland. In 2009, the 'Akihime' and 'Seolhyang' were examined again. In 2008, flower bud initiation rate was above 90.0% for all cultivars except for 'Akihime' (83.3%). Fruit harvest commenced 1 st of October 2008 and average fruit weight was consistently > 20g except for 'Sachinoka' (18 g). By mid-November, plants of 'Seolhyang' and 'Akihime' produced 222-260 more grams of fruit compared to other cultivars, with 'Seolhyang' having the earliest production. In 2009 experiment, flower bud initiation rates of 'Akihime' and 'Seolhyang' plants were 85.4% and 82.4%. Due to the earlier planting in 2009, fruit harvest commenced on 8 September (one month earlier than in 2008) and extended over 10 weeks. Yield and fruit numbers of 'Akihime' and 'Seolhyang' were 397.7 g, 22.7 and 331.7 g, 19.8, respectively. Results of this study indicate that exposure to SD photoperiods and relatively cool temperatures at HE can increase autumn fruit production in SD strawberry cultivars 'Akihime' and 'Seolhyang'.Additional key words: autumn fruit production, flower induction, Fragaria, high elevation, short-day treatment Hort. Environ. Biotechnol. 52(3):259-264. 2011.