Heat tolerance and cold tolerance of cultivated potatoes measured by the chlorophyll-fluorescence method

Abstract

Heat and cold tolerances were determined for 13 clones of the commonly cultivated potato, Solanum tuberosum L. Five clones were considered to be adapted to warm climates and the others to cool climates only in terms of their ability to produce tubers. The decrease in the rate of the induced rise in chlorophyll fluorescence after heating leaves at 41°C for 10 min was used to measure relative heat tolerance, and the decrease following chilling at 0°C was used to measure relative cold tolerance. The warm-adapted clones all showed enhanced heat tolerance compared with the cool-adapted clones. Higher heat tolerance was also correlated with a greater tolerance towards a cold stress of 0°C and it is suggested that the warm-adapted clones were selections showing an increased generalized capacity to withstand environmental stresses of several kinds rather than a specific genotypic adaptation to tolerate warm temperatures. Heat and cold tolerances were also determined for several other species of potato cultivated in the Andean region of South America. Of these, S. phureja, which is found at low altitudes on the eastern slopes of the Andes, showed a tolerance to heat comparable to that of the warm-adapted clones of the common potato, the two most heat tolerant of which contained some phureja in their parentage. Diploid and triploid species of cultivated potatoes were considerably more cold tolerant than the clones of the common potato, a tetraploid. The genetic variability for heat and cold tolerance in cultivated and wild potatoes is discussed in relation to increasing the tolerance of the potato to these stresses.

Effect of Leaf Detachment on Chlorophyll Fluorescence during Chilling Experiments

“…This slope is obtained by the difference in relative Chl fluorescence between two time points as explained by Smillie and Hetherington (9). Therefore, the results of this paper are expressed as changes in slopes to enable comparison with previous observations of Smillie et al (2,3,(8)(9)(10).…”

“…Changes in Chl fluorescence have been used to rank chilling tolerance in plants (2,3,(8)(9)(10) and this ranking is made by comparing the time for FR to decrease by 50% (3). Table II shows the ranking obtained from both detached and attached leaves.…”

“…The detached leaves lost some 50% of their total ionic content. Finally, detachment alters the ranking of the species with regard to their chilling tolerance.There has been much interest in the use of room temperature Chl fluorescence as a probe for chilling injury (2,3,(8)(9)(10). In the procedure developed by Smillie and coworkers (8-10) assess chilling tolerance in plants, fluorescence is measured on detached leaves stored at 0°C in the dark.…”

“…There has been much interest in the use of room temperature Chl fluorescence as a probe for chilling injury (2,3,(8)(9)(10). In the procedure developed by Smillie and coworkers (8)(9)(10) assess chilling tolerance in plants, fluorescence is measured on detached leaves stored at 0°C in the dark.…”

Evaluating yield and some traits of potato in prevent freezing cropaid of Jiroft area

“…Damage in the early stages and after flowering is less effective in reducing of the performance. Because in the primary stages of growth, regrowth is possible (Franks, 1985;Hetherington et al, 1983). However, freezing temperatures, the ultimate performance can be effective at every stage of growth (Hetherington et al, 1983).…”