The physiological and proteomic characteristics of oilseed rape stem affect seed yield and lodging resistance under different planting densities and row spacing

Abstract

Lodging is an important factor that restricts the yield of rapeseed and the mechanical harvesting. To explore agricultural practise and mechanisms that can synergistically improve the rapeseed yield and lodging resistance, a conventional plant type HZ 62 was selected in 2016–2017, and HZ 62 and an erect‐leaf type 1,301 were grown in 2017–2018. The planting density was set as main plots at 15 × 104 plants ha1 (D1), 30 × 104 plants ha‐1 (D2) and 45 × 104 plants ha−1 (D3), with the row spacing as sub‐plots of 15 cm (R15), 25 cm (R25) and 35 cm (R35). The results showed that with increased density and narrowed row spacing, the radiation utilisation efficiency (RUE) of the population and seed yield were greatly increased. Compared with that at D1R25, the yield of HZ 62 at D3R15 was increased by 19.00% and 22.53%, respectively, in 2016–2017 and 2017–2018, whereas the yield of 1,301 rose by 31.98%. The influence of the RUE on the seed yield reached the peak at flowering stage. With increased planting density and narrowed row spacing, the lodging index of HZ 62 declined. The lodging index of 1,301 was increased with higher density and declined with narrowed row spacing. Compared with D1R25, the averaged lodging index across different parts of HZ 62 at D3R15 declined by 15.03% and 10.80%, respectively, in 2016–2017 and 2017–2018, and that of 1,301 was increased by 25.47%. Compared with D1R25, the stem proteomics during the flowering stage showed the expression of photosynthesis‐related proteins (A0A078FHG9, A0A078JZM9 and A0A078JQI2) up‐regulated, that consistent with Rubisco, SPS and FBPase activities; proteins related to phenylpropanes metabolism, A0A078IWR4 of HZ 62 and A0A078JWZ9 of 1,301 increased that consistent with POD activity, which resulted in more sucrose, starch and lignin in the stem at D3R15. Moreover, the protein related to cellulose synthesis (A0A078I4D9), the activity of β‐1,3‐glucanase and content of cellulose in the stem were up‐regulated in HZ 62 but down‐regulated in 1,301, contrary to the variation in the stem lodging index. The cellulose synthesis differed between the varieties in different treatment combinations of planting density and row spacing. This was the key process by which planting density and row spacing influence the lodging of rapeseed varieties with varied plant architecture.

High plant density increases sunlight interception and yield of direct-seeded winter canola in China

“…At the visible floral bud stage, IS was 85% in the lowest density (15 plants m -2 ), while higher plant densities (more than 60 plants m -2 ) increased IS to 92-94% (Figure 3). IS achieved 92% for all tested densities at flowering, demonstrating that the light environment of the canola canopy was similar to treatments by adjusting canopy plasticity at the population level (Kuai et al, 2021;Menendez et al, 2021). From flowering to maturity, low densities (less than 60 plants m -2 ) resulted in low IS under a dense layer of green pods, which was attributed to enhanced floral branching (Li et al, 2017).…”

“…Canola has been a vital source of edible vegetable oil for human consumption owing to its high nutritional value (Song et al, 2020;Zhang et al, 2019). Compared to canola transplanting, which has been a traditional cultivation practice and yet labor intensive in China (Kuai et al, 2021;Wang et al, 2015), mechanized direct seeding can reduce winter canola production costs and increase production efficiency (Wang et al, 2015). However, the mechanized direct-seeding area only accounts for a relatively low proportion of the total winter canola farming area (Li et al, 2018).…”

“…Crop lodging is a considerable obstacle to the increase in canola production. As the population density increased, canola lodging risk increased, leading to low seed yield (Kuai et al, 2021). However, some studies on winter canola demonstrated that the increase in plant density did not curtail lodging resistance (Khan et al, 2017;Kuai et al, 2016;Li et al, 2018;Menendez et al, 2021).…”

“…Regardless of some research on seed yield, sunlight interception, and lodging risk of winter canola as affected by planting density (Dellero et al, 2021;Kirkegaard et al, 2018;Kuai et al, 2021;Wang et al, 2015), there are few studies on the characteristics of a wide range of canola population densities, including suboptimum or excessive densities, in the same field conditions. This study aimed to (i) determine the canola yield, sunlight interception, and lodging resistance under varying planting densities; (ii) investigate trade-offs among relatively higher plant density, yield, and sunlight interception and lodging resistance of winter canola; and (iii) evaluate the beneficial plasticity of improving canola yield as much as possible for direct-seeding canola plantation in China.…”

Genetic analyses and prediction for lodging‑related traits in a diverse Iranian hexaploid wheat collection

“…The following pathways have been identified based on the rice reference genome: starch and sucrose metabolism, zeatin biosynthesis, amino sugar and nucleotide sugar metabolism, and carbon metabolism. Based on various studies, carbon metabolism, and starch and sucrose are effective on the lodging resistance in plants 78 – 80 . There are two types of carbon assimilated structural carbohydrates and non-structural carbohydrates (NSCs).…”