Genotype‐aggregated planting improves yield in Jerusalem artichoke (Helianthus tuberosus) due to self/non‐self‐discrimination

Abstract

Accumulating evidence indicates that plants are capable of self/non‐self and kin/stranger discrimination. Plants increase biomass of and resource allocation to roots when they encounter roots of conspecific non‐self‐neighbors, but not when they encounter self roots. Root proliferation usually occurs at the expense of reproductive investment. Therefore, if clonal crops are capable of self/non‐self‐discrimination, spatially aggregated planting with seedlings of the same genotype may decrease root proliferation and produce a higher yield than planting without considering seedling genotype. To test this idea, we grew Helianthus tuberosus (Jerusalem artichoke) in pot and field conditions and examined self/non‐self‐discrimination and the effectiveness of genotype‐aggregated planting. Plants grown in self pairs allocated less to root biomass than plants grown in non‐self pairs in both pot and field conditions; in field conditions, the self pairs produced 40% more tubers by weight than the non‐self pairs. When six sprouts from seed tuber of two different genotypes were grown together, with the two genotypes planted aggregately (AGG) or alternately (ALT), plants in the AGG group produced 14% more tubers than plants in the ALT group. These results suggest that spatial aggregation of genotypes increases tuber production in H. tuberosus . Because we found no evidence for trade‐offs between root biomass and tuber production, suppression of root proliferation may not be the only mechanism behind the benefits of genotype aggregation. By applying the concept of self/non‐self‐discrimination, farmers can increase crop production without additional external inputs or expansion of agricultural land use.

Differential effect of inter‐ and intraspecific competition on the performance of invasive and native Taraxacum species

“…We did not find evidence of kin recognition in the invasive Taraxacum species, in contrast to a previous study showing kin recognition in the invasive species Alternanthera philoxeroides (Zhang et al, 2019). This is not surprising considering that studies examining kin recognition have often reported conflicting results (Ehlers & Bilde, 2019;Fukano et al, 2019;Masclaux et al, 2010;Milla, Forero, Escudero, & Iriondo, 2009). It is probable that interaction with kin would differ between plant species with different reproductive and dispersal strategies, so the fitness advantage of kin recognition might be species specific.…”

“…The kin recognition hypothesis predicts that plants allocate fewer resources to the roots but more resources to leaf biomass or reproduction in the presence of kin than in the presence of non-related individuals (Fukano et al, 2019). It should be noted, however, that if two genotypes have differential competitive ability, one genotype will increase but the other will decrease root allocation when they grow together compared to when they grow with the same genotype (Ehlers & Bilde, 2019;Masclaux et al, 2010).…”

Detect thy family: Mechanisms, ecology and agricultural aspects of kin recognition in plants

“…As kin selection can lead to more cooperative traits in plants and greater group performance, its potential use in crop breeding could be considered (Murphy, Swanton, et al, 2017). Kin discrimination has been demonstrated in several crop species, for example, soybean (Murphy, Van Acker, et al, 2017), barley (Ninkovic, 2003), sorghum (Zhang et al, 2016), wheat (Zhu & Zhang, 2013, but see Fréville et al, 2019), rice (Yang et al, 2018) and Jerusalem artichoke ( Helianthus tuberosus , Fukano, Guo, Noshita, Hashida, & Kamikawa, 2019), with findings that kin‐interacting plants tend to exhibit more cooperative root systems. A question then arises: to what would extent crop selection for kin recognition and discrimination be an effective means to increase crop yields?…”

Field‐based individual plant phenotyping of herbaceous species by unmanned aerial vehicle

“…Because this experiment had different research purposes, some plants were paired or grouped, but these plants did not affect the growth of focal individuals grown singly and were omitted from the subsequent analyses. For more details, see our previous study (Fukano et al, 2019).…”