scholarly journals Estimation of Growth and Photosynthetic Performance of Two C4 Species (Pennisetum spicatum (L.) K鰎n. and Zea mays L.) under a Low Temperature Treatment

Phyton ◽  
2022 ◽  
Vol 91 (1) ◽  
pp. 45-55
Author(s):  
Abdulkhaliq Alshoaibi
1976 ◽  
Vol 56 (4) ◽  
pp. 795-798 ◽  
Author(s):  
C. M. BREUER ◽  
R. B. HUNTER ◽  
L. W. KANNENBERG

A single-cross maize (Zea mays L.) hybrid was grown under two photoperiods (10 and 20 h) at two constant temperatures (20 and 30 C). Rate of development was characterized by the number of days from planting to tassel initiation, tassel initiation to silking, and silking to maturity. Long photoperiod and low temperature independently increased the number of days between planting and tassel initiation. The interval between tassel initiation and silking was not affected by photoperiod, but was increased significantly by the low temperature treatment. During the grain filling period (silking to maturity), temperature had the principal effect, but a photoperiod by temperature interaction did occur. Although plants grown at 20 C required more days to reach maturity than those grown at 30 C, the filling period at 20 C was shorter under the 10-h photoperiod than under the 20-h photoperiod, but at 30 C, the 10-h photoperiod treatment had the longer filling period. The delay in development at the low temperature, although apparent at all three stages of development, was not of the same magnitude. When the delay in development at 20 C is expressed as a percent of time required at 30 C, the 20 C treatment took 28% longer between planting and tassel initiation than the 30 C treatment. The corresponding figures for days between tassel initiation and silking and between silking and maturity were 58 and 46%, respectively.


1979 ◽  
Vol 57 (21) ◽  
pp. 2387-2393 ◽  
Author(s):  
M. R. Thiagarajah ◽  
L. A. Hunt ◽  
R. B. Hunter

The effects of short-term temperature fluctuations on net photosynthetic rates (Pn) are described for a single-cross corn (Zea mays L.) hybrid (Harrow 691). The hybrid was grown at 25 °C and subjected to 4 days at either 15 or35 °C, and then maintained at 25 °C. Genotypic differences in tolerance of Pn to low temperature were studied using 12 hybrids of different maturities grown at 25 °C and subjected to 4 days at 15 °C.Following low temperature treatment. Pn was initially reduced by about 15% for leaves 5. 9. and 13 of hybrid Harrow 691. but completely recovered after 1 day at 25 °C. Following high temperature treatment, leaves 5 and 9 showed similar reductions in Pn whereas leaf 13 was not affected. The photosynthetic activity of the heat-stressed leaf 9 recovered after 1 day, but that of leaf 5 showed no recovery for 14 days at 25 °C.Among 12 hybrids. Pn of the newly matured leaf 7 was reduced after the low temperature treatment, but the reduction was more drastic for two late hybrids than for three early hybrids. Most hybrids showed complete recovery of Pn after 1 day at 25 °C. but genotypic differences were evident. The results reported indicate that further evaluation of the amount of genetic variation in temperature stability in corn could be carried out usefully.


1968 ◽  
Vol 48 (3) ◽  
pp. 597-609
Author(s):  
R. MORRIS ◽  
J. M. BULL

1. An investigation has been made of the factors which cause sodium loss from ammocoetes when they are immersed in de-ionized water at 1° and 10° C. 2. Sodium influx ceases when animals are first immersed in de-ionized water, but can recommence when the animal loses sufficient sodium to the environment. The concentration of sodium required for influx to take place decreases with succeeding periods of immersion in de-ionized water at 10° C. and reaches minimum equilibrium concentrations as low as 0.005 mM-Na/l. 3. Low temperature inhibits sodium influx and thus promotes net loss of sodium to de-ionized water. 4. Low temperature also decreases the initial loss of sodium to de-ionized water and probably lowers the permeability of the external surfaces of the animal to ions. This effect is small compared with the inhibition of ion uptake so that the combined result is to increase the net loss of sodium from the animal. 5. Since animals lose calcium to de-ionized water and show a decreased rate of sodium loss when calcium salts are added, it is believed that the high rates of sodium loss in de-ionized water are attributable to the effect of calcium on permeability. 6. Lack of calcium may also explain why animals which have been depleted of sodium by low-temperature treatment take up sodium much faster at higher temperatures from dilute Ringer solutions than from pure sodium chloride solutions. 7. When animals lose ions to de-ionized water at low temperature, sodium and chloride are lost from the extracellular space, whilst the muscle cells lose potassium. These ions are recovered into the extracellular space when animals are allowed to take up ions at 10° C. from diluted Ringer solution later.


Author(s):  
M. F. Khairullin ◽  
E. A. Koval ◽  
I. Y. Levitskaya ◽  
M. G. Gadjiev ◽  
B. A. Sultonov

The study was aimed at developing a technology for preparing various semi-finished products from pork meat using low-temperature processing "Su-Vid". The main physicochemical indicators, functional-technological and structural-mechanical characteristics of semi-finished products, the chemical composition of semi-finished products and finished products were identified and determined experimentally, and organoleptic analysis was carried out. The data indicate that the use of low-temperature processing significantly affects the characteristics of manufactured products, which improves its performance. In particular, pork semi-finished products prepared at low temperatures are characterized by the yield: steak – 93.9%, ribs – 92.6%, in comparison with the control regime, 7.5 and 6.2% higher. The complex of data obtained showed that the samples of semi-finished pork, according to the experimental regimes of heat treatment, in terms of safety, fully meet the requirements of TR TS 034/2013. Analysis of semi-finished pork products showed that products prepared using the Su-Vid technology had high organoleptic characteristics, taste and sensory characteristics. During the storage of semi-finished products, minor changes in proteins and fats, as well as organoleptic, sanitary and microbiological characteristics, took place. As a result, a bone steak was developed in the Caucasian marinade and pork ribs in the Monte Ritz marinade made using the Su-Vid technology. The results allow us to judge that this technology is quite promising and has a positive effect on the characteristics of manufactured products. The widespread introduction of this technology in the meat industry will allow the development of semi-finished products and products of high quality, nutritional and biological value compared to products manufactured by traditional methods, as well as reduce production costs.


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