Protein and Starch Content of 20 Wheat (<i>Triticum aestivum</i> L.) Genotypes Exposed to High Temperature Under Late Sowing Conditions

Abstract

A total of 20 spring wheat genotypes were evaluated under three growing conditions (optimum, late and very late) at the research farm of the Wheat Research Center, Bangladesh to assess the variation in grain yield, protein and starch content under heat stress. All genotypes were significantly affected by high temperature stress in late and very late sowing conditions, resulting in a decrease in days to heading and maturity, ultimately affecting yield, protein and starch content. Considering yield performance, genotype 'E-8' was best under optimum (6245 kg ha -1 ), late (5220 kg ha -1) and very late sowing (4657 kg ha -1 ) conditions while 'E-40' was the worst. With respect to yield reduction, genotype 'E-72' was heat-tolerant (13% yield reduction) while 'Prodip' (49% yield reduction) was heatsusceptible. On the other hand, it was found that the percentage protein increased as heat stress increased. Under heat stress, genotype 'E-65' and 'E-60' had the highest and lowest protein content (15.5% and 12%), respectively. With respect to starch content, 'Prodip' and 'E-37' had the highest while 'E-14' and 'E-72' had the lowest content (64.8% vs. 62.9%), respectively in all sowing conditions.

Physiological and Biochemical Responses to Heat Stress on Barley Seedlings and Their Impact on Growth and Yield

“…The major impact of high temperatures on shoot growth is a severe reduction in the length of the first internode, resulting in the premature death of plants (Hall, 1992). Our findings related to dry matter reduction under heat stress are in agreement with observations by other reports on wheat Hossain and Teixeira da Silva (2012) and Hakim et al (2012). Our results are in agreement with the view that heat stress is one of the most important causes of reduced yield and dry matter production in wheat Al-Khatib and Pallsen (1984).…”

“…Elevated temperature lengthened the duration of grain filling with reduction in kernel growth leading to losses in kernel density and weight by up to 7% in spring wheat (Guilioni et al, 2003). Similar reductions occurred in starch, and grain quality in other cereals under heat stress (Maestri et al, 2002), Spiertz et al (2006) and Hakim et al (2012) found that high temperature followed by drought (soil moisture deficit) affected all stages of wheat and barley cultivars from germination through to reproduction of crop when sown late resulting in drastic reduction in yield. Reinhardt et al (2013) reported that high temperatures (30°C) at flowering resulted in a significantly reduced number of kernels and kernel yield per plant.…”

Phenology, Growth and Yield of Three Wheat (Triticum aestivum L.) Varieties as Affected by High Temperature Stress

“…Under high temperature, the crop completes its life cycle much faster than under normal temperature conditions (Fischer, 1985;Hakim et al, 2012;Hossain et al, 2009Hossain et al, , 2011Hossain et al, , 2012aHossain et al, , 2012bHossain et al, , 2012cNahar et al, 2010;. Delayed planting in a sub-tropical region such as Pakistan, India, Bangladesh, etc.…”

“…In LS, required DB was reduced the most, by 14% in 'BARI Gom-26' and the least in 'BARI Gom-25' by 4%. Hakim et al (2012) evaluated 20 wheat cultivars in same agro-climatological conditions and noticed that the life span of all wheat cultivars were reduced in LS due to high temperature stress (> 25°C) at the reproductive stage. sometimes minimum and maximum temperature ranged between 8-9°C and 20-19°C, respectively (Fig.…”

“…The Intergovernmental Panel on Climate Change (IPCC) estimates that by 2050, there will be changing rainfall patterns with increasing temperatures, flooding, droughts and salinity that would cause rice production to decline in Bangladesh by 8% and wheat by 32%, against 1990 as the base year (CCC, 2009). Several research findings noticed that temperature below (<10°C) or above (>25°C) the optimum (12 to 25°C) alter phenology, growth and development and finally reduce the yield of existing Bangladeshi wheat varieties (Hakim et al, 2012;Hossain et al, 2009Hossain et al, , 2011Hossain et al, , 2012aHossain et al, , 2012bHossain et al, , 2012cNahar et al, 2010;. Thus, heat is the greatest threat to food security in Bangladesh where wheat is the second most important food grain and where population is rapidly increasing (Indexmundi, 2011).…”