排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
The evidence that indicates a close association between nitrogen nutrition and the Photosynthetic rate of single rice leaves (Table 1) shows that the photosynthetic rate is related to the nitrogen content on a dry weight basis or on a leaf area basis, Photosynthesis of single leaves can be analyzed in terms of a series of diffusion resistances, i.e., stomatal, mesophyll, and carboxylation (1, 3, 6). Nitrogen nutrition may affect either one of these or more than two at the same time. Nitrogen nutrition affects mainly the mesophyll resistance, and the stomatal resistance to a lesser extent, in cotton, beans, and maize (10) while it affects both the stomatal and mesophyll resistance in sugar beet (8). 相似文献
2.
The aim of this work was to study the time course and pattern of fruit growth and the evolution of some of the chemical attributes such as soluble solids, acidity, and anthocyanin content in Ribes magellanicum plants growing in a natural environment near Ushuaia city, Tierra del Fuego (Argentina). Fruit growth and composition presented significant changes along the days from the full bloom phase. Fresh and dry fruit weight exhibited a typical double sigmoid curve. The first period of rapid fresh fruit growth was from full bloom phase until 28 days after, followed by a lag period until 42 days from the full bloom phase, and then by a second period of rapid increase until 56 days from the full bloom phase. Then, fresh fruit weight increased slowly (days 70–98 from the full bloom phase), reaching its maximum. Afterwards, fresh fruit weight decreased significantly until the end of the summer, and the fruiting period approximately ended 112 days from full bloom phase. On a dry weight basis the maximum fruit biomass was reached 98 days from the full bloom phase. Evolution of fruit growth was related with the compositional changes evaluated. By day 98 from the full bloom phase, soluble solids (17.5°Brix) and anthocyanin content (240.1 mg/100 g fruit fresh weight) were at their maximum, while at this time the total titratable acidity was at a minimum (0.4%). The results obtained not only contribute to the knowledge of the quantitative content of anthocyanin, a metabolite with nutraceutical value, but also give some tools for the definition of the optimal harvest time of R. magellanicum fruits, which it is important for fruit destination. 相似文献
3.
Paola Lax Juan C. Rondan DueñasNorma B. Coronel Cristina N. GardenalPaula Bima Marcelo E. Doucet 《Crop Protection》2011,30(11):1414-1420
The existence of races within the species Nacobbus aberrans sensu Sher has been confirmed; however, there is no consensus on a consistent system for race determination. Four plant species previously used as differential hosts in some N. aberrans race tests (tomato, pepper, sugarbeet and potato) were tested for susceptibility to seven nematode populations from Argentina. Plants were inoculated with second-stage juveniles and kept under glasshouse conditions at 21 °C for 90 days. The parameters evaluated (root gall index, egg mass index, and reproduction factor) in different nematode populations and plants showed significant differences. The reproductive fitness of the nematode populations differed among the plants that showed some degree of susceptibility. The results showed that N. aberrans comprises populations differing in host preference. Based on the nematode populations’ behaviour on these hosts, two groups were distinguished: i) populations that multiplied on all hosts, ii) populations that did not multiply on potato. The present work contributes to the analysis of criteria for developing a differential host test. 相似文献
4.
Monteros-Altamirano . Yumisaca-Jimnez F. Aucancela-Huebla R. Coronel J. Corozo-Quionez L. Cungun K. 《Genetic Resources and Crop Evolution》2022,69(3):1069-1087
Genetic Resources and Crop Evolution - Ecuador is one of the centers of diversity for wild and cultivated potatoes. Three micro-centers of diversity were previously identified based on germplasm... 相似文献
5.
Shouichi Yoshida Victoria Coronel Francisco T. Parao Evangelina de los Reyes 《Soil Science and Plant Nutrition》2013,59(4):381-386
Measurement of CO2 concentration in air at 25 em below and 100 em above the canopy of a good rice crop indicated that a severe CO2 deficit occurred around the photosynthetic surface of crop when light intensity was high. Soil CO2 flux as measured by the soda lime method in a closed system ranged from 3.9 to 5.7 g.m-2. day-1 under flooded conditions and from 6.0 to 8,6g.m-2 .day-1 under drained conditions. Cropped soil released more CO2 than bare soil under both flooded and drained conditions. The estimated contribution of soil CO2 to gross photosynthesis was 6%, for the flooded soil and 7% for the drained soil or a contribution of 9 and 12% to net dry matter production. These results together with other information indicate that atmospheric CO2 is the most important source of CO2, in crop photosynthesis, soil CO2 released into atmosphere Is second most important, and soil CO2 absorbed by plant roots is almost negligible. 相似文献
6.
Fertility in Holstein × Gyr cows in a subtropical environment after insemination with Gyr sex-sorted semen 总被引:1,自引:1,他引:0
Mellado Miguel Coronel Francisco Estrada Alfredo Ríos Francisco G. 《Tropical animal health and production》2010,42(7):1493-1496
Breeding records, including 649 inseminations during fall and winter at a dairy farm in a subtropical area of Western Mexico
(24o N; 24°C, mean annual temperature 24°C) were analyzed to document effects of sex-sorted semen from commercial Gyr bullls,
estrus synchronization protocol, inseminator, sire and environmental conditions on fertility of crossbred cows (Holstein ×
Gyr). Percentage of services resulting in pregnancies decreased sharply when sex-sorted semen was used (22.7 vs. 37.7%; P < 0.01). Although statistically not significant (P = 0.31), cows whose first insemination was in November experienced a numerically greater reduction (21 percentage points)
in pregnancy rate compared to cows whose first insemination occurred in December. Substantial increases in services per pregnancy
(4.71 ± 1.35 vs. 2.13–2.43; P < 0.01) were associated with the warmer month of the study period, November, compared to other winter months. Pregnancy rates
of cows regardless of semen category (33%) were not affected by sire, temperature–humidity index and estrus synchronization
protocol. Cows inseminated by one inseminator had higher pregnancy rates (P < 0.01) than cows inseminated by other two technicians. The sorted sperm produced 91% (142/156) female offspring. It was
concluded that, under the field conditions of the present study, pregnancy rate with sexed semen was 15 percentage points
lower than pregnancy rates using conventional semen, with 91% of female calves derived from sexed sperm. 相似文献
1