Increasing grain yield of oats by independent culling for harvest index and vegetative growth index or unit straw weight

Summary Most variation in grain yield of oats is due to variation in harvest index and vegetative growth index, but the latter traits are negatively associated. Therefore we used independent culling levels to select oat genotypes with high levels of vigor traits and a desirable level of harvest index in an attempts to maximize grain yield. Harvest index and vegetative growth index or harvest index and unit straw weight were selected at various culling levels. Intensive selection for harvest index resulted in high harvest index but no grain yield improvement, because the selected lines had poor vigor. Intensive selection for vegetative growth index or unit straw weight resulted in high biomass but low harvest index.The most effective combination of culling levels was to select 25% of the original population for harvest index and, subsequently, to select for vegetative growth index or unit straw weight at an 8% intensity in the remnant population.Journal Paper No. J-11272 of the Iowa Agric. and Home Econ. Exp. Stn., Ames, IA 50011. Project 2447. This work was supported in part by the World Food Institute, Iowa State Univ., in the form of a Senior Fellowship for the senior author.     

Genetic analysis of tissue culture traits in barley cv. 'Lenins'

The barley cultivar ‘Lenins’ was found to be a genotype showing high shoot regeneration ability in cultures derived from immature embryos. Five cultivars different from ‘Lenins’ in shoot regeneration ability were reciprocally crossed with ‘Lenins’ and the inheritance of tissue culture traits was investigated. F₂ plants showed continuous distributions in callus growth and percentage of shoot regeneration, suggesting that these traits were controlled by polygenes. The F₂ population, derived from a cross between ‘Lenins’ and ‘6721′, showed a monogenic segregation for the number of regenerated shoots, and the segregation ratio fitted 1:2:1. Tissue culture traits of ‘Lenins’ were controlled by several genes, whereas the number of regenerated shoots related to the efficiency of shoot regeneration is controlled by one major gene.     

Chemical studies on antioxidant mechanism of curcumin: analysis of oxidative coupling products from curcumin and linoleate

As a part of a research project on the antioxidant mechanism of natural phenolics in food components, curcumin, a turmeric antioxidant, was investigated in the presence of ethyl linoleate as one of the polyunsaturated lipids. During the antioxidation process, curcumin reacted with four types of linoleate peroxyl radicals. Six reaction products were observed in the reaction and subsequently isolated. Their structures were determined by physical techniques, revealing that they have novel tricyclic structures, including a peroxyl linkage. On the basis of the formation pathway for their chemical structures, an antioxidant mechanism of curcumin in polyunsaturated lipids was proposed, which consisted of an oxidative coupling reaction at the 3'-position of the curcumin with the lipid and a subsequent intramolecular Diels--Alder reaction.     

The feeding habits of collembola along decomposition gradients using stable carbon and nitrogen isotope analyses

We measured the natural stable carbon (C) and nitrogen (N) isotope ratio patterns of collembola and the organic substrates of their habitats and potential food sources in a warm temperate coniferous forest. Based on previous studies, we classified collembola into successional classes along litter decomposition gradients: early colonizers, late colonizers, and dominants-throughout. The stable C and N isotope ratios of late colonizers exceeded those of early colonizers, and those of the dominants-throughout were intermediate between early and late colonizers, which is consistent with previous studies on two macro-invertebrates, earthworms and termites. The C and N isotopic signature differences in collembola may reflect food resource partitioning along decomposition gradients.     

C(18) acetylenic fatty acids of Ximenia americana with potential pesticidal activity

Bioactivity-driven fractionation of the CHCl(3) extract of the root of Ximenia americana, using the brine shrimp lethality test (BST) and hatchability test with Clavigralla tomentosicollis eggs, gave C(18) acetylenic fatty acids 1 and 2. 1 is octadeca-5-ynoic acid (tariric acid). 2 is a novel ene-ene-yne-ene acetylenic fatty acid (10Z,14E,16E-octadeca-10,14,16-triene-12-ynoi c acid). The structures of 1 and 2 were assigned from the MS and NMR data. Fractions that are rich in acetylenic fatty acids inhibited the hatching of C. tomentosicollis eggs.     

Fungal ingrowth on forest floor and decomposing needle litter of Chamaecyparis obtusa in relation to resource availability and moisture condition

Fungi play an important role in litter decomposition in forest ecosystems and studies are needed to follow the changes in hyphal abundance during litter decomposition and examine the factors regulating the ingrowth of hyphae in litter. The purposes of the present study are to demonstrate the patterns of needle decomposition of Chamaecyparis obtusa in terms of the vertical distribution of fungal biomass and chemical properties within litter horizons (L1, L2, F, and H layers) and fungal ingrowth and succession in relation to organic chemical and nitrogen dynamics during needle litter decomposition over a one-year period. A further aim is to assess the effect of moisture and availability of organic matter on live hyphal length, during 1 year of decomposition. Live hyphal length was correlated to holocellulose concentration in four litter horizons. In a litter bag experiment, total (live plus dead) hyphal length increased during decomposition which was correlated to the concentrations of nitrogen, lignin, holocellulose, and soluble carbohydrate in the litter. The 12-month period over which decomposition was measured was divided into four seasons and the correlation between the water content and live hyphal length was evaluated for each period. The length of live hyphae was correlated to the water content of litter in all four periods. The slopes of regression lines between the water content and live hyphal length were positively correlated to the mean concentrations of soluble carbohydrate of each period, suggesting that the growth of live hyphae was highly dependent on the moisture condition of litter, and under moist conditions on the availability of soluble carbohydrate in the litter. The decrease in the slopes during decomposition can be ascribed to ecophysiological traits of fungi responsible for decomposition in these periods.     

Effects of grazing adaptation on herbage intake,milk production,and body weight change in lactating dairy cows after turning out to pasture in early spring

The present study investigated the effects of adaptation to grazing in early spring on the herbage intake, milk production, and body weight changes in lactating dairy cows. The experiment included 12 Holstein lactating cows during early spring. Six cows were allowed to gradually adapt to grazing (ADP) over 10 days. They were allowed to graze on a pasture for 4 h during the first week and for 19 h during the remaining 3 days (adaptation period). During the 10-day period, the remaining six cows were housed in a barn (CON). Cows in both groups received adequate silage, hay, and concentrate during the adaptation period. Subsequently, cows in both groups were allowed to graze together for 19 h for 4 weeks (experimental period). No cow received supplements during the experimental period. In the first week of the experimental period, the ADP cows showed a higher herbage intake than the CON cows. During the subsequent weeks, there were no differences in herbage intake between the two groups. At the start of the experimental period, milk production and body weight of the ADP cows were higher than those of the CON cows, and this difference lasted until the end of the experiment.     

Example of an adenocarcinoma developed in the gastric lymph nodes of a harbor seal Phoca largha

SUMMARY: Adenocarcinomatous growths comprising glandular cavities surrounded by cuboidal to low columnar cells and a large amount of mucus produced by the mucous cells, were observed in the the gastric lymph nodes of a harbor seal Phoca largha. The seal was stranded on the coast of Toyama Bay, Sea of Japan, on 2 March, 1998. Necroscopic examination also showed the animal had significant signet ring cell carcinoma in the stomach, as has been reported elsewhere. The adenocarcinoma may have developed from metastatic cells arising in the gastric carcinoma.     

The economic value of days open in Holstein cows in Japan based on simulated changes in conception rate

Increasing herd‐life length and culling parity with increasing conception rate (CR) is necessary to increase lifetime profit from dairy cow production. Economic values of days open (DO) were determined by calculating changes in fertility traits, herd‐life length, and milk yield when the simulated CR were changed in increments of 1% from ?5% to 5% from the basal levels, which were obtained for Hokkaido and regions other than Hokkaido separately. When CR increased, number of artificial inseminations, DO, and milking length decreased. Furthermore, culling parity, and annual milk yield increased. Herd‐life length increased in Hokkaido and decreased in the other regions. The economic values of CR were 1,623.8 to 946.8 yen and of DO were 857.4 to 399.0 yen. Relative economic values of milk yield to days open per genetic standard deviation were higher in the other regions than in Hokkaido where the economic effect of selection for DO was expected to be equal to selection for 305‐day milk yield and herd life. If the survival rate of multipara cows in the other regions increases, then the economic value of DO would similarly increase in Hokkaido.