Nutrient uptake and distribution by bread and durum wheat under drought conditions in South Australia

Abstract

Summary. An important limitation to the production of durum wheat in South Australia is its poor adaptation to the alkaline, sodic soils of the cereal belt, which often results in nutrient imbalances in the crop. A field experiment was conducted at Palmer, South Australia, to measure the nutrient uptake and distribution between grain and straw of 3 bread wheat cultivars and 9 cultivars and breeding lines of durum wheat. The purpose of the work was to characterise the patterns of nutrient uptake and to examine whether there were major, consistent differences between bread wheat and durum wheat. Rainfall during the growing season was below average and the crops suffered from drought stress after anthesis. Plants were marginally deficient or deficient in nitrogen (N), phosphorus (P) and zinc (Zn), and boron (B) concentrations were high. Compared with bread wheat, durum wheat had a very much higher concentration of sodium (Na), higher concentrations of calcium (Ca) and sulfur (S), but lower concentrations of potassium (K), magnesium (Mg), manganese (Mn) and copper (Cu). Total amounts of P, Zn and Na in the shoot continued to increase throughout the growing season with significant increases occurring during grain filling, whereas there was little increase in the amount of N, K, B and Mn during grain filling. The maximum rate of nutrient uptake occurred before the time of maximum crop growth rate, and was in the order K (10.1 weeks after sowing), N (10.6), P (11.3), Mn (12.0), Zn (12.5) and B (14.6); maximum growth rate occurred at 14.8 weeks. There was no consistent difference between bread and durum wheat in the partitioning of nutrients to the grain. The importance of N and Zn uptake to the growth of the durum wheat genotypes was shown by significant correlations between maximum uptake rates of these nutrients and maximum crop growth rate, with the strongest correlation being with Zn. Growth rate was not correlated with uptake rates of other nutrients. A number of genotypes of durum wheat had maximum rates of Zn and Mn accumulation up to twice those of the current commercial genotypes. Some of these lines have yielded well at Zn- and Mn-deficient sites which indicates that the micronutrient efficiency of durum can be improved. Late in the season the experiment showed signs of infection by crown rot (Fusarium graminearum Schw. Group 1). Durum wheat showed more severe symptoms than bread wheat and the number of white heads in durum wheat was inversely correlated with the concentration of Zn in the shoot during the pre-anthesis period.

Plant and microbial strategies to improve the phosphorus efficiency of agriculture

“…9a; Rose et al 2007;Rose et al 2010). The P-harvest index of cereals is generally higher than 50% and sometimes up to 90% for field grown crops in Australia (Batten and Khan 1987;Zubaidi et al 1999;Santonoceto et al 2002;Ryan and Angus 2003) and similarly ranged from 57% to 86% for various rice genotypes grown in the field ( Fig. 9b; Rose et al 2010).…”

“…9a). Proportionately more P is mobilized in P-starved than in P-sufficient plants (Elliot et al 1997), although P-harvest index may also be reduced by factors that reduce grain harvest index such as dry spring periods or disease (Zubaidi et al 1999). In the study by Rose et al (2010), P harvest index was highly correlated with grain harvest index suggesting that exploiting genetic variability for this trait may be counterproductive.…”

REVIEW: Biofortification of Durum Wheat with Zinc and Iron

“…Compared with bread wheat, durum wheat tends to accumulate more Zn and Fe (Zubaidi et al 1999;Conti et al 2000) as well as Cd (Li et al 1997;Meyers et al 1982). It is still unknown why accumulation of Zn, Fe, and especially Cd occurs to a greater extent in durum than bread wheat.…”

“…These observations suggest that retranslocation of micronutrients deposited in shoot tissues plays a critical role in the grain accumulation of micronutrients. In wheat, ≤70% of the amount of Zn in vegetative plant parts is remobilized (Grewal and Graham 1999;Zubaidi et al 1999), whereas only 20% of Fe is remobilized in rice (Grusak et al 1999). Genotypic differences in grain yield may also affect grain concentrations of micronutrients despite a similar root uptake rate or shoot accumulation of micronutrients.…”

Impact of ancestral wheat sodium exclusion genes Nax1 and Nax2 on grain yield of durum wheat on saline soils

“…Its yield is more affected by salinity than bread wheat (Francois et al 1986;Maas and Grieve 1990). Durum wheat is less able to exclude Na + (Zubaidi et al 1999b;, a trait associated with salt sensitivity in the Triticeae (Gorham et al 1990;Dvorák et al 1994). Durum wheat lacks the Na + -excluding locus Kna1 which enables hexaploid wheat to maintain lower leaf Na + and a greater K + to Na + ratio than durum wheat (Dvorák et al 1994;Dubcovsky et al 1996).…”