Hydraulic conductance differences among sorghum genotypes to explain variation in restricted transpiration rates

2014 ◽  
Vol 41 (3) ◽  
pp. 270 ◽  
Author(s):  
Sunita Choudhary ◽  
Thomas R. Sinclair

Sorghum (Sorghum bicolor L.) is an important crop for production in dryland regions of the globe. Traits identified in many sorghum lines that apparently make them adapted for dryland conditions are restricted transpiration rate both early in the soil drying cycle and under high atmospheric vapour pressure deficit. It was hypothesised that these responses could be a result of differences in hydraulic conductance of the plants: those with low hydraulic conductance would be more likely to express restricted transpiration rates. The location of the lower hydraulic conductance in the plant could also be important with a low conductance in the leaf xylem to stomata pathway possibly being more advantageous than in the root. In this study, the amount and location of the hydraulic conductance was measured in 20 sorghum genotypes. Those genotypes that expressed an early decrease in transpiration rate with soil drying had greater plant and leaf hydraulic conductance than those genotypes that had the later decreases in transpiration rate, which was in contrast with what was hypothesised. However, sorghum genotypes that segregated between two groups based on expression of a maximum transpiration trait also segregated based on their hydraulic conductance. Those genotypes that expressed the maximum transpiration trait had lower hydraulic conductance for the intact plant and in the leaves.

1977 ◽  
Vol 4 (6) ◽  
pp. 889 ◽  
Author(s):  
BJ Forde ◽  
KJ Mitchell ◽  
EA Edge

Rates of water use [g H2O (g dry wt leaf)-1 h-1] of young plants of maize, paspalum, perennial ryegrass, Westerwolds ryegrass, peas, white clover and lucerne were measured during the day under controlled climate conditions with ample water available to the plant. Plants were grown and observations made with day/night temperatures of 32.5/27.5°C, 27.5/22.5°, 22.5/17.5°, and 17.5/12.5°C with a day/night vapour pressure deficit (VPD) of the air of 10/2mbar. Water use measurements were also made at 27.5/22.5° and 17.5/12.5°C under day/night VPD regimes of 5/2 and 15/2 mbar. Irradiance during the 12-h day was 170 W m-2 (400-700 nm). Further water use determinations were made at the four temperature regimes under 10/2 mbar VPD and an irradiance of 60 W m-2 (400-700 nm). For a given species, transpiration rates increased with temperature at constant VPD under both irradiance environments, by factors ranging from 1.4 to 2.3. Transpiration rates of maize and paspalum (C4) were lower at a given temperature than were the rates of the C3 species, while lucerne and clover had the highest rates. Water use by lucerne was 2.5 to 3.5 times that of maize. Transpiration rates of maize and paspalum were lower under 60 W m-2 than under 170 W m-2 but irradiance had little effect on transpiration rate of the C3 species. Though transpiration rate generally increased with increasing VPD, the difference in rates between plants at 5 mbar and 10 mbar VPD was much greater than between 10 mbar and 15 mbar. The physiological adaption of different species to their growth environment is discussed, and the implications of the results with reference to water loss by young, single-spaced plants in the field is outlined.


1996 ◽  
Vol 76 (1) ◽  
pp. 123-125 ◽  
Author(s):  
W. P. McCaughey ◽  
M. C. Therrien ◽  
R. Mabon

After a series of hot, dry years in the late 1980s a study was conducted to assess the suitability and yield stability of forage sorghum (Sorghum bicolor L. Moench.) in southern Manitoba. The effects of genotype and environment on DM yield of seven forage sorghum genotypes were evaluated (1990–1992) in six different environments. Genotype, environment and genotype × environment accounted for 3.9% (P < 0.0001), 84.8% (P < 0.0001) and 3.3% (P < 0.001) of the total variation in DM yield, respectively. The fact that environment accounted for most of the variability in DM yield and that relative rankings of varieties differed across environments indicated that yield was unstable. Forage sorghum produced acceptable DM yield only in years which were warmer (> 2700 CHU) than average (2200–2600 CHU) for southern Manitoba. Forage sorghum is not recommended for southern Manitoba unless the climate warms to where 2700 CHU are consistently accumulated during the growing season. Key words: Forage, sorghum, sorghum-sudangrass, C4, temperature, yield


2020 ◽  
Vol 8 (2) ◽  
pp. 347
Author(s):  
Farastika Unjunan Muli ◽  
Efri Efri ◽  
Muhammad Syamsoel Hadi ◽  
Radix Suharjo

One of the diseases that often found in sorghum plants is anthracnose disease caused by Colletotrichum sp. The purposed of this study was to determine the effect of adding micro fertilizer and the use of several sorghum genotypes on the intensity of anthracnose disease. The study was conducted in Sukanegara, Tanjung Bintang, South Lampung in April 2017 - February 2018 and at the Laboratory of Plant Diseases and Pests, Faculty of Agriculture, University of Lampung. The treatments were arranged using a randomized block design in a split plot design (3 times replications), the main plot was micro nutrients (with micro addition and without micro addition) and 15 subgroups of sorghum genotypes (Numbu, Samurai 1, GH3, UPCA, GH4, P / I WHP, GH6, Super 2, GH13, P / F 51-93-C, Super 1, GH5, Mandau, GH7, and Talaga Bodas). The results showed that the addition of "ZincMicro" micro fertilizers to sorghum plants did not affect the intensity of anthracnose disease, however there were differences in the intensity of anthracnose diseases between sorghum genotypes. Numbu Genotype, GH 3, and GH 13 were relatively more resistant to anthracnose disease than the other genotypes.


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