Physiological Basis of the Difference in Net Photosynthetic Rate of Leaves between Two Maize Strains

2000 ◽  
Vol 38 (2) ◽  
pp. 199-204 ◽  
Author(s):  
Hua Jiang ◽  
Da-Quan Xu
1989 ◽  
Vol 67 (6) ◽  
pp. 1689-1697 ◽  
Author(s):  
T. J. Tschaplinski ◽  
T. J. Blake

Physiological determinants of productivity, including net photosynthesis, root/shoot partitioning of photosynthate, and leaf retention were investigated for three Populus deltoides Bartr. × nigra L. (DN 2, DN 22, DN 15) and two P. balsamifera L. × deltoides Bartr. (Jackii 4, Jackii 7) hybrids. Performance of the different hybrids was compared under controlled greenhouse conditions and in the field. There was a 2.4-fold difference in biomass production between the faster growing DN 2 and the slower growing DN 15 after 100 days growth in the greenhouse, and a 1.5-fold difference after the 1st year's growth in the field. When coppice regrowth of the two Jackii hybrids was compared after 143 days under field conditions, the biomass production of Jackii 4 was 2.2 times that of Jackii 7 and net photosynthetic rate per unit leaf area was 50 % higher than that of Jackii 7 over most of the summer. Many physiological and morphological factors contributed to the more vigorous growth of coppice DN 2 and Jackii 4. These included vigorous initial root growth relative to shoot growth, the ability to maintain higher xylem pressure potentials, net photosynthetic rate, and transpiration rate. These factors may have delayed leaf senescence and late-season photosynthetic decline of older leaves until later in the growing season. The possible causal sequence of physiological events contributing to the difference in productivity and the use of these factors for the early selection of productive hybrids or genotypes are discussed.


2009 ◽  
Vol 17 (3) ◽  
pp. 474-478
Author(s):  
Qun-Long LIU ◽  
Chan-Juan NING ◽  
Duo WANG ◽  
Guo-Liang WU ◽  
Hong-Mei ZHANG ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yinli Bi ◽  
Huili Zhou

AbstractA well-developed canopy structure can increase the biomass accumulation and yield of crops. Peanut seeds were sown in a soil inoculated with an arbuscular mycorrhizal fungus (AMF) and uninoculated controls were also sown. Canopy structure was monitored using a 3-D laser scanner and photosynthetic characteristics with an LI-6400 XT photosynthesis system after 30, 45 and 70 days of growth to explore the effects of the AMF on growth, canopy structure and photosynthetic characteristics and yield. The AMF colonized the roots and AMF inoculation significantly increased the height, canopy width and total leaf area of the host plants and improved canopy structure. AMF reduced the tiller angle of the upper and middle canopy layers, increased that of the lower layer, reduced the leaf inclination of the upper, middle and lower layers, and increased the average leaf area and leaf area index after 45 days of growth, producing a well-developed and hierarchical canopy. Moreover, AMF inoculation increased the net photosynthetic rate in the upper, middle and lower layers. Plant height, canopy width, and total leaf area were positively correlated with net photosynthetic rate, and the inclination angle and tiller angle of the upper leaves were negatively correlated with net photosynthetic rate. Overall, the results demonstrate the effects of AMF inoculation on plant canopy structure and net photosynthetic rate.


2002 ◽  
Vol 53 (6) ◽  
pp. 643 ◽  
Author(s):  
M. J. Robertson ◽  
J. F. Holland ◽  
S. Cawley ◽  
T. D. Potter ◽  
W. Burton ◽  
...  

Canola tolerant to the triazine group of herbicides is grown widely in Australian broad-acre cropping systems. Triazine-tolerant (TT) cultivars are known to have a yield and oil content penalty compared with non-TT cultivars. This study was designed to elucidate the crop physiological basis for the yield differences between the two types. Two commercial cultivars, near-isogenic for the TT trait, were compared in a detailed growth analysis in the field, and 22 crops were compared for phenology and crop attributes at maturity. In the growth analysis study, the TT trait was found to lower radiation use efficiency, which carried through to less biomass at maturity. There were minimal effects on leaf area development and harvest index, and no effect on canopy radiation extinction. Across the 22 crops, where yield varied from 240 to 3400 kg/ha in the non-TT cultivar, yield was on average 26% less in the TT cultivar due to less biomass produced, as there was no significant effect on harvest index. The difference in oil content (2-5%) was greater in low oil content environments. Flowering was delayed by 2-10 days with a greater delay being in later flowering environments. Quantification of the physiological attributes of TT canola allows the assessment of the productivity of different cultivar types across environments.


Plant Science ◽  
2005 ◽  
Vol 169 (3) ◽  
pp. 523-531 ◽  
Author(s):  
K. Mosaleeyanon ◽  
S.M.A. Zobayed ◽  
F. Afreen ◽  
T. Kozai

2020 ◽  
Author(s):  
Zhou Zijuan ◽  
Su Peixi ◽  
Wu Xiukun ◽  
Shi Rui ◽  
Ding Xinjing

Abstract Background: The Tibetan Plateau is highly sensitive to elevated temperatures and has experienced significant climate warming in the last decades. While climate warming is known to greatly impact alpine ecosystems, the gas exchange responses at the leaf and community levels to climate warming in alpine meadow ecosystems remain unclear.Results: In this study, the alpine grass, Elymus nutans, and forb, Potentilla anserina, were grown in open-top chambers (OTCs) for three consecutive years to evaluate their response to warming. Gas exchange measurements were used to assess the effects of in-situ warming on leaf- and community-level photosynthetic carbon assimilation based on leaf traits and photosynthetic physiological parameters. We introduced a means of up-scaling photosynthetic measurements from the leaf level to the community level based on six easily-measurable parameters, including leaf net photosynthetic rate, fresh leaf mass per unit leaf area, fresh weight of all plant leaves, the percentage of healthy leaves, the percentage of received effective light by leaves in the community, and community coverage. The community-level photosynthetic carbon assimilation and productivity all increased with warming, and the net photosynthetic rate at the leaf level was significantly higher than at the community level. Under elevated temperature, the net photosynthetic rate of E. nutans decreased, while that of P. anserina increased.Conclusions: These results indicated that climate warming may significantly influence plant carbon assimilation, which could alter alpine meadow community composition in the future.


Sign in / Sign up

Export Citation Format

Share Document