Recruitment and growth of the sardine Sardinops melanostictus fluctuated markedly in the Sea of Japan and adjacent waters between 1978 and 1993. Stock size was calculated using Virtual Population Analysis and average body length in each age class was determined by the number of annual rings on the scales. There is an inverse correlation between average water temperature at a depth of 50 m in the coastal area of the mainland of Japan in winter (January to March) and recruitment R defined as the number of individuals at 1 year old. There is also an inverse correlation between spawning stock size E and reproductive success in (R/E). A multiple regression model using spawning stock size and water temperature in winter as independent variables can explain 73% of variance in reproductive success. It suggests that both density‐dependent and density‐independent factors perform important roles determining reproductive success. There is an inverse correlation between body length and stock size and this suggests that there is a density‐dependent effect on the growth of the sardine.
Capsicum chinense is a domesticated hot pepper species in the Capsicum genus that originated in the Amazon and is consumed in USA, the Caribbean and South America. Although a characteristic of this species is high pungency, some non-pungent or lowpungent strains, called ''Aji Dulce'' (sweet pepper in Spanish), exist in the Caribbean region. In the present study, low-pungent C. chinense accessions were analyzed in order to elucidate the genetic mechanisms responsible for low pungency. All low-pungent C. chinense accessions in this study carried non-functional alleles of putative aminotransferase (pAMT), which catalyzes the formation of vanillylamine from vanillin in the capsaicinoid biosynthetic pathway. These low-pungent accessions produced capsinoids, low-pungent capsaicinoid analogs. The pamt mutation in each strain was characterized using allele-specific markers, and one novel pamt allele (pamt 7 ) was identified. The pamt 7 had a new hAT family transposon insertion in the second exon region, which caused the loss of pAMT expression. pamt 7 is apparently an ancestral allele for pamt 6 because the 7-bp insertion in pamt 6 can be regarded as a footprint of the transposon. A phylogenetic analysis of pamt alleles was performed to examine their relationships. Combined with previously reported pamt alleles, the Tcc family transposon insertion and its excision were involved in the generation of various pamt alleles in C. chinense. A phylogenetic analysis of pamt alleles showed that at least five occurred within C. chinense after speciation of the Capsicum genus. In conclusion, the results of the present study identified pamt as the main and most frequent gene controlling low pungency in C. chinense. Allelic variations in loss-of function pamt and their wide distribution demonstrated the potential of C. chinense bioresources for genetic improvements to pungency and metabolic profiles in hot pepper breeding programs.
Kidokoro, H., Goto, T., Nagasawa, T., Nishida, H., Akamine, T., and Sakurai, Y. 2010. Impact of a climate regime shift on the migration of Japanese common squid (Todarodes pacificus) in the Sea of Japan. – ICES Journal of Marine Science, 67: 1314–1322. Following a climate regime shift (RS) in 1989 in the northwest Pacific and Sea of Japan, the main spawning grounds of the Japanese common squid (Todarodes pacificus) shifted from inshore areas off Honshu Island to the Tsushima Strait, and the stock size increased. Migration patterns of T. pacificus occurred after the RS, based on tagging experiments conducted in July to September of 1984 and 1987–1991, are examined using monthly shifts in average latitude of recapture sites every 10 d. Before the RS, recaptures were in the central Sea of Japan and in inshore areas off Honshu Island, but after the RS, there were no recaptures inshore off Honshu Island. The average latitude of the recapture sites in September was about 36–37°N before the RS and north of 40°N (near the release sites) after the RS. It is likely that the location of the spawning grounds has changed.
This research reveals that the up-regulated expression of multiple capsaicinoid biosynthetic genes in pericarp tissue leads to the elevation of total capsaicinoid content in chili pepper fruit. Capsaicinoids are health-functional compounds that are produced uniquely in chili pepper fruits. A high capsaicinoid level is one of the major parameters determining the commercial quality and health-promoting properties of chili peppers. To investigate the mechanisms responsible for its high contents, we compared an extremely pungent cultivar 'Trinidad Moruga Scorpion Yellow' (MY) with other cultivars of different pungency levels (Fushimi-amanaga, Takanotsume, Red Habanero). Capsaicinoid concentrations were markedly higher in MY fruit (23.9 mg/g DW) than in other pungent cultivars including 'Red Habanero' (HB) fruit (14.3 mg/g DW). Comparative analysis of MY and HB reveals that both cultivars accumulated similar capsaicinoid concentrations in the placental septum, with that in the HB pericarp (1.8 mg/g DW) being markedly lower than that in the placental septum (69.1 mg/g DW). The capsaicinoid concentration in HB fruit is dependent on the placental septum, as reported in other accessions. Therefore, even though placental septum tissue contains high capsaicinoid concentrations, those in the pericarp and seeds attenuated its total content. In contrast, the MY pericarp exhibited a markedly higher concentration (23.2 mg/g DW). A qRT-PCR analysis revealed that multiple capsaicinoid biosynthetic pathway genes (Pun1, pAMT, KAS, and BCAT) were strongly up-regulated in placental septum of pungent cultivars. The genes were expressed exclusively in the MY pericarp, but were barely detected in the pericarps of other pungent cultivars. Collectively, the present study indicates that the up-regulated expression of these genes not only in placental septum but also in pericarp plays an important role in driving capsaicinoid accumulation in the whole fruit.
To understand the factors affecting the incidence of blossom-end rot (BER), the effect of the Ca/K ratio (4/12-12/4, in me·L -1 ) in nutrient solutions and Ca concentration in fractions in the distal part of young tomato fruits immediately before BER symptoms appear were investigated for three seasons. The rate of BER incidence increased with a decrease in the Ca/K ratio in the supplied solutions in the summer and spring, but little difference was observed in the winter. Ca concentration was highest in winter and lowest in summer, and the concentration in fractions decreased with a decrease in the Ca/K ratio of the solutions. When the results of all three experiments were pooled, among the fractions, water-soluble Ca concentration was found to have the highest significance in the relationship to BER incidence. The risk of BER incidence in rapidly growing tomato increased to a critical level when water-soluble Ca in the distal part of the fresh fruit decreased to less than 0.20 μmol·g -1 FW. Multiple-regression analysis revealed that the concentration of water-soluble Ca, which is predominantly recovering apoplastic or cytoplasmic Ca 2+ , and total Ca, which has been translocated during fruit development, are significantly affected by solar radiation and Ca concentration in the supplied solution rather than air temperature.
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