On characterizing root function in perennial horticultural crops

Abstract

While root-order approaches to fine-root classification have shown wide utility among wild plants, they have seen limited use for perennial crop plants. Moreover, inadequate characterization of fine roots across species of domesticated perennial crops has led to a knowledge gap in the understanding of evolutionary and functional patterns associated with different fine-root orders. METHODS: We examined fine-root traits of common horticultural fruit and nut crops: Malus ×domestica, Prunus persica, Vitus vinifera, Prunus dulcis, and Citrus ×clementina. Additional roots were sampled from 33 common perennial horticultural crops, native to tropical, subtropical, and temperate regions, to examine variation in 1st-and 2nd-order absorptive roots. RESULTS: First-order roots of grape and 1st-and 2nd-order roots of apple and peach were consistently thin, nonwoody, mycorrhizal, and had high N:C ratios. In contrast, 4th-and 5th-order roots of grape and 5th-order roots of apple and peach were woody, nonmycorrhizal, had low N:C ratios, and were thicker than lower-order roots. Among the 33 horticultural species, diameter of 1st-and 2nd-order roots varied about 15-fold, ranging from 0.04 to 0.60 mm and 0.05 to 0.89 mm respectively. This variation generally was phylogenetically conserved across plant lineages. CONCLUSIONS: Collectively, our research shows that root-order characterization has considerably more utility than an arbitrary diameter cutoff for identifying roots of different functions in perennial horticultural crops. In addition, much of the variation in root diameter among species can be predicted by evolutionary relationships.

Intraspecific Leaf Trait Variation across and within Five Common Wine Grape Varieties

“…Therefore, the analysis here is limited in informing how longer-term climatic, edaphic, and/or management-related changes influence grape leaf trait expression. Crop responses to a multitude of chronic, acute, and interacting environmental drivers underpin longer-term agroecological resistance or resilience environmental change [ 56 ], with crop leaf [ 29 , 57 ], root [ 27 ], or phenological traits [ 28 , 58 ] being central in meditating these responses. Indeed, enhancing the phenological variability and other aspects of functional diversity has been identified as a key climate change mitigation strategy for vineyards globally [ 30 ].…”

“…This study evaluated LES trait relationships in wine grape ( Vitis vinifera L.): one of the world’s most commercially important crops which, along with table grapes, is currently estimated to cover ~6.95 million ha of agricultural land globally. Considerable research on wine grapes to date has sought to quantify the extensive diversity in above- [ 26 ] and belowground functional traits [ 27 ], phenology [ 28 , 29 ], and physiognomic forms [ 26 ], that exists across the ~1100 varieties spanning multiple climatic zones [ 30 ]. More specifically, leaf physiological, chemical, and morphological trait variations have long been the focus of many studies in the areas of crop biology and viticulture [ 31 ].…”

Enriched CO2 and Root-Associated Fungi (Mycorrhizae) Yield Inverse Effects on Plant Mass and Root Morphology in Six Asclepias Species

“…Lower order roots are more involved in nutrient uptake and mycorrhizal associations. In contrast, higher order roots (i.e., root order > 3) have higher C-N [36], which may suggest a greater response to enriched CO 2 .…”

Ethylene modulates root growth and mineral nutrients levels in trifoliate orange through the auxin-signaling pathway

“…Roots constitute an integral part of the plant axis, typically residing underground (Britannica, 2021). They serve crucial functions such as the absorption of water and nutrients (Lavely et al, 2020), anchoring plants to the ground (Ian et al, 2021), and storing large quantities of food. Additionally, roots play a significant role in response to abiotic or biotic stress (Xie et al, 2021;Yan et al, 2022).…”