The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization.
The objective of this study was to elucidate variability among soybean cultivars in yield response at different planting densities in reference to branch development. We investigated the main stem and branch seed yield and the branching characteristics of determinate Hokkaido and indeterminate US cultivars at the Rakuno Gakuen University in Ebetsu. In 2009 and 2010, two Japanese and two US cultivars were grown at three densities from 9.5 to 20 plants m
The activity of soluble invertase, and the variation in glucose, fructose and sucrose contents in onion bulbs (Allium cepa) during long-term storage at 10 degrees C and 20 degrees C were investigated. Invertase activity increased progressively after 8 weeks to 0.084 and 0.092 nkat/g fresh weight (FW), then sharply to 0.29 and 0.35 nkat/g FW at 20 degrees C and 10 degrees C, respectively, and remained high during 5 weeks. Then, activity decreased abruptly to 0.039 and 0.041 nkat/g, and remained low during the last 8 weeks and close to that observed initially. Glucose increased to 17.73 and 14.62 mg/g FW after 4 weeks at 20 degrees C and 10 degrees C, respectively, then decreased sharply between week 5 and week 7 to 4.13 and 4.91 mg/g FW, respectively, and remained rather stable ranging from 9 and 10 mg/g FW at both temperatures. Fructose showed a similar pattern and was 14.8 and 21.68 mg/g FW at 20 degrees C and 10 degrees C, respectively. Between week 10 and week 24, fructose ranged from 5 and 6 mg/g FW, and from 6 and 7 mg/g FW at 20 degrees C and 10 degrees C, respectively. Sucrose increased to 19.63 and 14.43 mg/g FW at 20 degrees C and 10 degrees C, respectively, decreased during 3 weeks, and then increased randomly from 5.69 to 9.42 mg/g FW at 20 degrees C, but remained in a steady state at 10 degrees C ranging 5.03 +/- 0.78 mg/g FW. During the last 6 weeks, the sucrose content was higher at 20 degrees C than at 10 degrees C. The fructose-glucose ratio varied during the first 8 weeks but remained at a steady level during the last 16 weeks. The (glucose+fructose)/sucrose ratio increased randomly at 10 degrees C, whereas at 20 degrees C the ratio increased during 10 weeks then decreased progressively during the final 14 weeks.
Wheat flour was blended with triticale flour and baking tests were performed. When 18.3% of triticale flour was blended with wheat flour, the greatest bread height (mm) and specific volume (cm 3 /g) were obtained. Triticale flour was fractionated into water solubles, gluten, prime starch, and tailings by acetic acid (pH 3.5) fractionation. Baking results indicated that only the water solubles fraction produced the same baking performance as the original triticale flour. Several types of triticale flour were blended with wheat flours, and the breadmaking tests and measurement of amylase activities were compared. Baking results appeared to be related to ␣-amylase activity of triticale flour.
We investigated how two planting patterns, twin row (TR) and narrow row (NR), affected maize grain yield compared with conventional row (CR) cultivation at five different planting densities, ranging from 7 to 12 plants/m2, over 2 years using early and late cultivars. For all the planting patterns, the relationship between grain yield and planting density could be fit using the quadratic curve Y = a (X − b)2 + c at the <1% level of significance, where a represents grain yield response to planting density, and c represents the maximum yield. Regardless of the cultivar’s maturation period, the magnitude of a was smaller for TR than for NR and CR. Although the late cultivar had a higher c value than the early cultivar, the a value and annual difference were larger. For the early and late cultivars, TR at 10.8 and 9.9 plants/m2, respectively, easily achieved stable high grain yields. The large magnitude of the grain yield response to planting density for the late cultivar was caused by the large decrease in the number of grains per ear and the harvest index at an above optimum planting density. This large decrease and instability in yield‐related traits resulted from a high maximum leaf area index, the frequent mutual shading of leaf blades and the large differences between the years.
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