Breeding Amaranth for Biomass: Evaluating Dry Matter Content and Biomass Potential in Early and Late Maturing Genotypes

Abstract

Amaranth (Amaranthus spp.) is a promising biomass crop for silage and biogas production. Under long-day conditions, it exhibits prolonged vegetative growth. To evaluate the breeding potential of amaranth for biomass production, we characterized phenotypic variation in biomass yield components, quantitative genetic parameters, and the relationships between traits. We conducted field trials of 10 biomass-type genotypes exhibiting a ‘giant’ growth habit derived from spontaneous hybridization between genetically diverse parents, and used the variety “Bärnkrafft” as check. We observed two contrasting growth patterns: Bärnkrafft is a variety for grain production and was characterized by a short vegetative growth followed by a long seed ripening. In contrast, the biomass genotypes displayed a long vegetative growth followed by a short seed ripening. We observed strong correlations between dry matter content and stem diameter (r =−0.78, p < 0.01) and between plant height and biomass score (r = 0.95, p < 0.001). High values for broad-sense heritability of stem diameter (H2 = 0.88) and plant height (H2 = 0.92) suggest that the dry matter content and yield can be improved by indirect phenotypic selection. We hypothesize that selection for dry matter content and yield implies a trade-off between earliness and photoperiod sensitivity. Hence, dry matter content should be improved first by recurrent selection, which can be then combined with short-day genes to improve dry matter yield. Overall, this work provides an avenue to the breeding of biomass amaranth.

Characterization of Nutritional Potential of <em>Amaranthus </em>sp. Grain Production

“…The reason may be the different varieties used in our trial, meaning A. cruentus and A. hypochondriacus versus A. triclor. Our results concerning plant height frame within a narrower range, and mean plant heigths have lower values, compared to those reported by Baturaygil et al (2021) in amaranth hybrids, between 109-253 cm [37], Bashyal et al (2018) between 75.98-167.14 cm [38], and Génalis and Seguin (2008) in eight amaranth genotypes, between 143-168 cm [39]. The number of leaves (36.33-199.66) corresponding to results reported by Bashyal et al ( 2018) is much higher [38] compared to values presented in our study.…”

Characterization of Flowering Time in Genebank Accessions of Grain Amaranths and Their Wild Relatives Reveals Signatures of Domestication and Local Adaptation

“…In addition, amaranth can be used as a silage crop in both tropical and temperate regions, for which a high biomass is advantageous [14]. Recently, we reported two contrasting growth patterns in amaranth under long-day conditions; a grain-type amaranth cultivar showed early flowering and short plant height, suggesting photoperiod insensitivity, while biomass-type amaranths showed delayed or no flowering and reached a tall plant height, suggesting the effect of short-day genes [26]. Kulakow and Jain [27] postulated that flowering time in amaranth is controlled by three major genes, with a single gene controlling reduced vegetative growth and two genes controlling photoperiodic response in multiple backcross-derived populations between A. cruentus and the wild relative A. retroflexus.…”

“…The species is also suitable for mechanical harvest because of a shorter plant height than the other grain amaranths. Breeding programs for biomass amaranth should consider a trade-off between earliness for high dry matter content and photoperiod sensitivity for improved dry matter yield [26], which can be combined in crosses between these two types of amaranths that differ in photoperiodic response. To this end, earliness can be selected from A. cruentus and South American accessions as donors of mild photoperiod sensitivity, since the delay in flowering time of highly photoperiod-sensitive accessions did not additionally contribute to plant height (Figure 4A).…”

Genetic resources and breeding approaches for improvement of amaranth (Amaranthus spp.) and quinoa (Chenopodium quinoa)

“…These clusters could be used in a hybridization program to select good parents having maximum variability and select transgressive segregants from the population developed to increase the yield. Phenotypic characterization of amaranth genotypes based on biomass yield and related traits laid the future for trait-focused breeding programs ( 145 ). Many species of amaranth were studied for the complete chloroplast genome sequences using simple sequence repeats by Chaney et al ( 146 ).…”