Genotypic variations appear in fine root morphological traits of Cryptomeria japonica trees grown in a common garden

• Published in: Ecological research Vol. 39; no. 5; pp. 717 - 729
• Main Authors: Nakahata, Ryo, Azuma, Wakana A., Tanabe, Tomoko, Kawai, Kiyosada, Hiura, Tsutom
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.09.2024; Blackwell Publishing Ltd
• Subjects: Absorptivity; Acclimation; Acclimatization; Branching; Cedar; Cryptomeria japonica; Exudates; Exudation; fine root morphology; Gardens & gardening; genotypic variation; intraspecific variation; Morphology; Plant growth; Plant species; Plant tissues; Resource conservation; Roots; root branching order; Trees; Variation
• ISSN: 0912-3814; 1440-1703
• DOI: 10.1111/1440-1703.12492

Fine root morphological traits regulate the belowground resource acquisition strategies of trees. Therefore, investigating genotypic variations isolated from environmental variations within tree species helps in understanding how genotypic backgrounds affect intragenerational tree acclimation to the growing environment. Thus, this study aimed to clarify the effects of genotypic variations on the fine root morphology of three types of Japanese cedar (Cryptomeria japonica), which were derived from different provenances but were grown in a common garden. In the three geographically different provenances of C. japonica stands (Yanase, Yoshino, and Yaku), fine root morphological traits, such as root length and diameter and specific root length (SRL), were measured for each root up to the 4th branching order. Yaku cedar exhibited root traits distinct from the other provenances, such as growing longer and thinner roots in 1st root order to enhance root surface area. In addition, the SRL patterns with root orders and higher root tissue density suggested a resource conservation strategy. Yanase cedar demonstrated a significantly higher root branching ratio and specific root tips than the other provenances, indicating a strategy for investing resources in absorptive roots. Although Yoshino cedar had traits similar to those of Yanase cedar or intermediate between Yanase and Yaku cedars, high aboveground production may be achieved through nutrient acquisition with root exudates instead of absorptive root growth. Genotypic variations appeared in fine root morphological traits of C. japonica trees, even when grown in the same environments, implying distinct resource acquisition strategies characterized by each provenance. This study aimed to clarify the effect of genotypic variations on fine root morphology of three types of C. japonica (Yanase, Yoshino, and Yaku) under the same environmental conditions by measuring fine root morphological traits for each root up to 4th branching root order. Genotypic variations appeared in fine root morphological traits of C. japonica trees, even when grown in the same environments, implying distinct resource acquisition strategies characterized by each provenance.