Sources of heat tolerance amongst potato cultivars, breeding lines, and Solanum species

Abstract

This study assessed 46 potato cultivars, breeding lines and Solanum spp. for heat-tolerance using short-term growth rates and carbon assimilation measurements of young in-vitro-derived plants. Plants of the 46 clones and species were transferred from greenhouse conditions to controlled conditions set at 33/25° C day/night with 12 h photosynthetic photon flux density (PPFD) at 430--450/xmol m-2s -1 and an 8 h daylength extension (6/xmol m-2s-1), to inhibit tuberization. Twenty eight accessions were also grown in a 20/10°C controlled environment. Plants were harvested after 10 and 20 days and dry weights of the plant components were measured for plant growth analysis. Gas exchange (leaf net photosynthesis and maintenance dark respiration) and leaf chlorophyll fluorescence parameters (O, P, and T) were measured at 30 ° C. Amongst the 30 accessions grown at both hot and cool temperatures, only two accessions (Yungay and AVRDC 1287.19) produced more dry weight in the hot chamber than the cool chamber. Hot/cool ratios for net assimilation rate (NAR) and relative growth rate (RGR) exceeded unity in five and six accessions, respectively. For the 46 accessions grown under hot conditions, none had significantly greater values than those of the control clones for RGR and NAR. Differences between clones in maintenance respiration and net photosynthesis were more closely related to RGR, NAR, and total dry weight (TDWT) in clones which invested more dry weight in leaves and less in stems. Attributes of the chlorophyll fluorescence curve did not explain more of the clonal variation in RGR, NAR, and TDWT than did gas exchange parameters. No single gas exchange or fluorescence character explained more than 50% of the variability among clones for NAR, RGR, or TDWT, but combination of favourable attributes could improve potato heat tolerance in the future.

Early generation in vitro assay to identify potato populations and clones tolerant to heat

“…Varieties such as Tomasa Condemayta, and 396244.17 are good candidates for heat tolerance. These results are consistent with previous reports where Nowak and Colborne (1989) confirmed CIP breeding line LT2 as a heat resistant clone, Midmore and Prange (1991) noted that AVRDC 1287.19 produced more dry weight in the hot chamber than the cool chamber, and Carli et al (2009) confirmed Reiche, Tacna, and CIP 397077.16 as well-adapted clones for hot summer conditions of Central Asia.…”

Engineering heat tolerance in potato by temperature‐dependent expression of a specific allele of HEAT‐SHOCK COGNATE 70

“…Whilst cultivated potato is generally a cool climate crop, there is significant variation in response to heat stress between cultivars (Levy, ; Levy et al ., ; Marinus and Bodlaender, ; Mendoza and Estrada, ; Menzel, ; Midmore and Prange, ), in land races and wild potato species (Hetherington et al ., ; Mendoza and Estrada, ; Reynolds and Ewing, ) and in progeny clones from heat‐tolerant parents (Haynes and Haynes, ; Mendoza and Estrada, ; Morpurgo et al ., ; Veilleux et al ., ). Despite reported variation, we are unaware of any reports that identify QTL for heat tolerance in potato.…”

Assessment of morphophysiological traits for selection of heat-tolerant potato genotypes

“…There are two prerequisites for success of a breeding program aimed to develop heat-tolerant cultivars: choosing the most appropriate parents and using a reliable screening method in early generations (Hijmans, 2003;Levy and Veilleux, 2007). Previous studies indicated that it is possible to find sources for heat tolerance among potato varieties, breeding lines, and wild Solanum species (Gautney and Haynes, 1983;Levy, 1986;Levy et al, 1991;Reynolds and Ewing, 1989;Midmore and Prange, 1991;Tai et al, 1994), and it is also possible to breed heat-tolerant potato varieties using conventional breeding (Susnoschi et al, 1987;Levy et al, 1991;Haynes et al, 1992;Veilleux et al, 1997;Levy et al, 2001) and mutations (Das et al, 2000). Using a reliable selection method is crucial for success in a breeding program aimed at developing heattolerant potato varieties (Sattelmacher, 1983;Nowak and Colborne, 1989;Reynolds and Ewing, 1989;Veilleux et al, 1997;Levy and Veilleux, 2007).…”