Pavon 76 Bread Wheat–Rye Translocations Improve Field Root Biomass Production under Diverse Nitrogen Management Systems

Abstract

Th e plant root system is earmarked as key to the next Green Revolution. Field experiments were conducted in 2010-2011 and 2011-2012 to determine the impact of N management system on root growth in cultivar Pavon 76 (Pavon), bread wheat (Triticum aestivum L.), and wheat-rye (Secale cereale L.) translocations Pavon-1RS.1AL (1RS.1AL), and Pavon-1RS.1BL (1RS.1BL). Th e three genotypes were examined under organic N (manure) and synthetic N fertilizer regimes each at a high and low rate, and an unfertilized control. Th e translocated genotype 1RS.1BL had 23 and 9% higher total root biomass than Pavon in the 2010-2011 and 2011-2012 growing seasons, respectively. Compared to Pavon, root mass of genotypes 1RS.1AL and 1RS.1BL was 23.3 to 55.9 g m -3 higher in the top 40 cm of the soil profi le and 15.1 to 31 g m -3 higher in soil profi les below 40 cm. Th e 1RS translocations also had higher root dry mass than Pavon under synthetic N, low organic N and the unfertilized control. Mean genotype grain yields for both growing seasons ranged from 3.8 to 4.1 Mg ha -1 and there were no diff erences between 1RS lines and Pavon. Th ese studies show that the root system was enhanced without a subsequent loss of yield in a high yield potential environment; similar research is needed for low wheat yield potential environments.

Root system architecture in cereals: progress, challenges and perspective

“…This has been mostly observed in the crop pre-breeding research where the alien segments are known to provide a yield advantage, and then such advantage is underpinned due to the root traits. For example, the introduction of rye chromosome into bread wheat resulted in the development of cultivars with 1B.1R translocation, and introduction of alien segment from Agropyron elongatum as 7DL.7EL translocation, which have good drought adaptability due to the deeper roots (Kaggwa et al, 2015;Placido et al, 2013). As described in Ober et al (2021), the development of elite introgression lines for target root traits with similar above-ground behavior would provide valuable materials for evaluating the value of the new trait in different environments or production.…”

Genome‐wide dissection and haplotype analysis identified candidate loci for nitrogen use efficiency under drought conditions in winter wheat

“…These results corroborate that plant nitrogen uptake and use strongly depend on the soil moisture. The dynamic of nutrients in soil and plant water uptake are limited under low soil moisture, which results in low nutrient uptake independently of nutrient availability (da Silva et al, 2011;Kaggwa, 2013). The values of the NUErelevant traits (i.e., NUpE, NUtE, NRE, NUEBio, and NUE) were lower with HN fertilization, as described in various articles, reporting low NUE traits as the result of low values of the numerator and high denominator (available N or applied N) in NUE calculation (Voss-Fels et al, 2019).…”

“…The root system provides the plant with anchorage, competitiveness, and adaptation to stress. Furthermore, roots also have significant roles in soil exploration, stand establishment, below‐ground carbon sequestration, soil structure improvement, and maintenance of soil fertility by driving microbial processes (Kaggwa, 2013; Richard et al., 2015; Siddiqui et al., 2021). Improving RSA traits such as root length, biomass, and area have shown positive effects on plant photosynthetic features like high stomata density and lower canopy temperature.…”