Effects of high temperature stress during anthesis and grain filling periods on photosynthesis, lipids and grain yield in wheat

Table 2 Effect of temperature regimes [optimal temperature (24/14 °C) and high temperature (32/22 °C)] during anthesis (experiment I) and grain filling (experiment II) stages on unsaturation index of various lipid classes. Values shown are LSMEAN ± standard error of LSMEAN (n = 4). The LSMEANS followed by same letter(s) within each growth stage are not statistically significant at P ≤ 0.05

Polar lipid	Growth stages
	Experiment I: High temperature during anthesis stage		Experiment II: High temperature during grain filling stage
	Optimum temperature	High temperature	Optimum temperature	High temperature
MGDG	2.92 ± 0.006^a	2.89 ± 0.006^b	2.87 ± 0.007^a	2.80 ± 0.007^b
DGDG	2.79 ± 0.009^a	2.77 ± 0.009^a	2.72 ± 0.01^a	2.66 ± 0.01^b
PG	1.64 ± 0.008^a	1.57 ± 0 .008^b	1.69 ± 0.01^a	1.59 ± 0.01^b
PC	1.74 ± 0.02^a	1.82 ± 0.02^a	1.74 ± 0.01^a	1.70 ± 0.01^a
PE	1.81 ± 0.01^b	1.89 ± 0.01^a	1.87 ± 0.01^a	1.86 ± 0.01^a
PI	1.39 ± 0.01^a	1.41 ± 0.01^a	1.36 ± 0.004^a	1.35 ± 0.004^a
PS	1.29 ± 0.01^a	1.33 ± 0.01^a	1.31 ± 0.01^b	1.36 ± 0.01^a
PA	1.63 ± 0.02^a	1.69 ± 0.02^a	1.51 ± 0.03^a	1.53 ± 0.03^a

The unsaturation index of each lipid molecular species was calculated as the product of the amount of that lipid molecular species and the average number of double bonds per acyl chain, where the average number of double bonds per acyl chain was calculated by dividing the number of double bonds in the lipid molecular species by the number of acyl chains. Finally, the unsaturation index of a lipid head group class was calculated as the sum of the unsaturation indices of individual lipid molecular species in that class. MGDG Monogalactosyldiacylglycerol, DGDG Digalactosyldiacylgylcerol, PG Phosphatidylglycerol, PC Phosphatidylcholine, PE Phosphatidylethanolamine, PI Phosphatidylinositol, PS Phosphatidylserine, and PA Phosphatidic acid

ISSN: 1471-2229