Relationships of non‐structural carbohydrates accumulation and translocation with yield formation in rice recombinant inbred lines under two nitrogen levels

Abstract

Stem non-structural carbohydrates (NSCs) and its relationship with yield formation was investigated under low nitrogen (LN) and normal nitrogen (NN) treatments, using 46 recombinant inbred lines from Zhenshan 97 × Minghui 63 (Oryza sativa). Apparent contribution of transferred NSC to grain yield (AC(NSC) ) ranged from approximately 1 to 28% under LN and from 1 to 15% under NN. Concentration and total mass of NSC in stem (TM(NSC) ) at heading, apparent transferred mass of NSC (ATM(NSC) ) and AC(NSC) were larger under LN compared with NN. However, there was no significant difference in the apparent ratio of transferred NSC from stems to grain (AR(NSC) ). ATM(NSC) was positively correlated with grain yield, 1000-grain weight and AC(NSC) under both nitrogen levels, whereas AR(NSC) was highly correlated with harvest index and AC(NSC) . Leaf area contributed more strongly to grain yield compared with ATM(NSC) under both LN and NN. ATM(NSC) showed larger direct effects on grain yield under LN compared with NN. TM(NSC) at heading, small vascular bundles (SVBs) and spikelets per m(2) under LN had positive direct effects on ATM(NSC) . SVB and spikelets per m(2) under LN had larger and positive direct effects, and large vascular bundles had negative direct effects on AR(NSC) . TM(NSC) at heading and SVB under LN had positive direct effects on AC(NSC) . In brief, LN supply increased stem NSC accumulation and translocation to developing grain. Components of the source-sink-flow system showed different effects on NSC translocation and contribution to yield formation, depending on genotype and nitrogen level.

Evaluating Hyperspectral Vegetation Indices for Leaf Area Index Estimation of Oryza sativa L. at Diverse Phenological Stages

“…Transformation in the canopy reflectivity of different spectral parts is concurrent with the LAI and is often confounded through modification of the leaf chlorophyll contents during plant growth with increasing N fertilization (Jégo et al, 2012). Elevated N application generates taller plants with higher numbers of tillers and a greater leaf area, which requires more carbohydrates in the plant canopy (Pan et al, 2011). Not only the biophysical characteristics of vegetation, canopy architecture, atmospheric absorption, and scattering affect the canopy hyperspectral reflectance but so do the direction of incidence radiation and soil backgrounds (Carvalho et al, 2016).…”

Non-Structural Carbohydrates Accumulation in Contrasting Rice Genotypes Subjected to High Night Temperatures

“…During the vegetative phase and until heading, carbon assimilates are partially and temporally stored in stems and leaf sheaths in rice plants as NSC, which are sinked for all events involving since reproductive organ formation until grain development and maturation phase (Morita & Nakano, 2011;Zhang et al, 2016). For rice, there are studies showing that the stem NSC contribution to grain yield must reach 28% (Pan et al, 2011;Yoshida, 1981). Besides, there are indications that stem NSC at full heading stage of rice can increase the grain ripening ratio in those plants submitted to heat stress, increasing its grain yield stability (Morita & Nakano, 2011).…”

Robust phenotyping strategies for evaluation of stem non-structural carbohydrates (NSC) in rice

“…Management conditions that delay senescence (e.g. heavy nitrogen application) seem to have the opposite effect and suppress translocation of stem reserves, in effect decreasing their grain-filling contribution (Hirano et al , 2005; Fu et al , 2011; Pan et al , 2011). Contrasting with wheat research in which the agronomic role of stem fructans was established early and now informs wheat physiological breeding (Bidinger et al , 1977; Pask et al , 2012; Reynolds et al , 2012), studies on rice have not been able to clearly define aspects of stem reserves that are genetically tractable or capable of optimization and thereby valuable for varietal improvement.…”