Depositing ability of stem of winter wheat varieties of different periods of selection

V V Morgun,G A Priadkina,O V Zborivska

doi:10.15421/021936

Abstract

Adaptation of high-yielding winter wheat crops to changes in climatic conditions has great importance for food security of countries. The remobilization of stem assimilates for grain filling is one of the possible ways of increasing wheat yield in unfavourable environmental conditions. Field experiments in natural conditions with three old and three modern varieties of winter wheat were performed to compare depositing abilities of their stems. The objective of this study was a comparative analysis of the parameters of depositing capacity of stems of the main shoots for identification of the criteria for assessing grain productivity of winter wheat. The parameters of depositing capacity of the stem of the main shoots of three old winter wheat varieties (1997, 2003, and 2008) and three modern ones (2013, 2014 and 2016) were studied in field conditions with natural conditions of water supply (Kyiv Oblast, Ukraine). During the period of formation of reproductive organs (April and May), the amount of precipitation, respectively, was only 17% and 68% of long-term values and average monthly air temperature was 3–4 ºС higher than the climatic norm. We analyzed the variability of the parameters of depositing capacity of the stem of the main shoot and grain productivity of the ear of six wheat winter varieties which differed by time of selection. In unfavourable conditions during the period of formation of reproductive organs the modern winter wheat varieties had an 11% higher yield on average compared to the older ones. It was determined that the highest mass of grain from the ear of the main shoots (1.9–2.1 g) belonged to Odeska 267 variety, a drought-tolerant variety from earlier selection, and three modern varieties – Raihorodka, Prydniprovska and Darunok Podillia. It is demonstrated that these varieties also exceeded two old varieties (Podolianka and Yednist) by stem dry matter weight of main shoot at anthesis by 0.3–0.6 g. The highest content of non-structural carbohydrates at this phase was observed in Odeska 267, Raihorodka and Darunok Podillia varieties (273–307 mg/stem). Correlation analysis revealed the significant correlation between mass of grain from ear and dry matter of stem at anthesis and full ripeness, as well mass of grain from ear and the amount of non-structural carbohydrates at anthesis. Therefore, modern varieties of winter wheat and the drought-tolerant variety have higher yield, weight of dry matter of stem of the main shoot at anthesis and grain productivity of the ear, compared to old varieties. The results of this study indicate that the mass of dry matter of the stem of the main shoot at anthesis can be used as a marker of the grain productivity of winter wheat.

Highlights

Significant changes in weather conditions have been characteristic of the past decades
A high weight of grains per ear of the main shoot (1.9–2.1 g) of winter wheat plants which grew in drought conditions during the period of initiation of reproductive organs was observed in the old droughttolerant variety Odeska 267 and all three modern varieties (Table 1)
Varieties Odeska 267, Darunok Podillia and Raihorodka differed by the best grain filling: the weight of 1000 grains varied from

Summary

Introduction

Significant changes in weather conditions have been characteristic of the past decades. The amount of precipitation has decreased, compared with the 1980s (Lobell et al, 2011) Both of these factors contribute to the occurrence of droughts. Yields of important food crops – winter wheat – in drought conditions reduces on average by 21–32% (Zhang et al, 2018). Drought reduces the rate of photosynthesis and stomatal resistance, the assimilating surface area, causes the destruction of photosynthetic pigments and decreases the activity of antioxidant enzymes of thylakoid membranes of chloroplasts (Reynolds et al, 2015; Olsovska et al, 2016; Yan et al, 2016; Ouyang et al, 2017). It was shown that higher stem nonstructural (or water soluble) carbohydrate reserves compensated the loss of photosynthetic surface caused by influence of different factors (Esmaeilpour-Jahromi et al, 2012; Saeidi et al, 2012; Dodig et al, 2016)

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