How different pruning severities alter shoot structure: a modelling approach in young ‘Nonpareil’ almond trees

Abstract

Axillary meristem fate patterns along shoots, also referred to as shoot structure, appear to be fairly consistent among trees within a genotype growing under similar conditions. Less is known about shoot structural plasticity following external manipulations, such as pruning. The aim of this study on almond (Prunus dulcis (Mill.)) shoots was to investigate how pruning severity affects the structure of 1-year-old shoots that grew after pruning (regrowth shoots), the 2-year-old portion of shoots that remained from the previous year's growth after pruning (pruned shoots), and whether regrowth shoots reiterate the structure of the original 1-year-old shoots before pruning. Three pruning severities were imposed and the structures along the different shoots were assessed by building hidden semi-Markov models of axillary meristem fates. The structures of regrowth and pruned shoots depended on pruning severity, but maintained some of the original shoot characteristics. Regrowth shoots developed more complex structures with severe pruning, but had simpler structures than original shoots indicating progressive simplification with tree age. Pruned shoot structures were affected by the severity of pruning, by the structure when the shoots were 1 year old, and probably by local competition among buds. Changes in structure due to pruning can be modelled and be predictable.

Phenotyping Almond Orchards for Architectural Traits Influenced by Rootstock Choice

“…These methods analyze tree architecture as a succession of zones with a different proportion of node types whose arrangement is defined by transition probabilities, using branches as the study subject [16,[21][22][23]. This approach has been applied to almond under different circumstances [24][25][26]. Although these models are useful for describing and visualizing repetitive patterns in tree architecture and branching formation, they are difficult to incorporate into genomic analyses, such as genome-wide association studies (GWAS).…”

Unpruning improvement the quality of tea through increasing the levels of amino acids and reducing contents of flavonoids and caffeine

“…In plantation P2, the RLs of 52 metabolites in UPTTs were lower than in PTTs (VIP > 1, FC < 0.66, and P < 0.05), and the majority of these metabolites were flavonoids (28), followed by phenolic acids (8) organic acids (4) and nucleotides and derivatives (3), including kaempferin, cynaroside, quercitrin, phloretin, and isovitexin. In addition, the RLs of 58 metabolites in UPTTs were higher than in PTTs, and the majority of these metabolites were flavonoids (17), lipids (15) and phenolic acids (15), followed by lignans and coumarins (5) and tannins (3 metabolites), including tyramine, quillaic acid, kaempferitrin, coumarin, rutin and naringenin (VIP > 1, FC > 1.5, and P < 0.05) (Figure 5B). The high levels of serine and phenylalanine in UPTTs were in accordance with HPLC measurements.…”

“…(14), tannins (10), and terpenoids (2). They were further grouped into 30 sub-classes, including flavonols (34), free fatty acids (28), saccharides and alcohols (20), flavanols (18), flavonoid carbonoside (17), Lysophosphatidylcholine (15), proanthocyanidins (14), anthocyanins (9), and isoflavones (4).…”

“…It can affect the regulation of flavonoid biosynthesis, phenylpropanoid biosynthesis and amino acid metabolism ( 16 ). For example, the epigallocatechin gallate (EGCG) contents in tea manufactured from PTTs are significantly higher than in those from UPTTs ( 17 ). Additionally, the free amino acids, as well as the theanine, chlorophyll and floral-honey aromatic substance, levels in tea leaves of UPTTs are higher than those of PTTs, whereas the catechins levels are lower ( 18 ).…”

Proleptic and Sylleptic Shoot Formation Is Affected by Rootstock Genotype in Two-Year-Old Branches of Almond Trees

“…Negrón et al [13] reported that the pattern of shoot production and fruiting was determined by cultivar genotype. The formation of proleptic and sylleptic shoots has also been analyzed under different environments or experimental treatments, for example, water deficiency or pruning [14,15]. In peach (P. persica (L.) Batsch), it has been reported that more floral buds are produced on proleptic than sylleptic shoots [16].…”