Yield analysis of winter oilseed rape (Brassica napus L.): a review

https://hal.archives-ouvertes.fr/hal-01422741/document

Dynamics of Nitrogen Uptake and Mobilization in Field-grown Winter Oilseed Rape (Brassica napus) from Stem Extension to Harvest I. Global N Flows between Vegetative and Reproductive Tissues in Relation to Leaf Fall and their Residual N

Summary
Seed oil content is an important agronomic trait in rapeseed. However, our understanding of the regulatory processes controlling oil accumulation is still limited. Using two rapeseed lines (zy036 and 51070) with contrasting oil content, we found that maternal genotype greatly affects seed oil content. Genetic and physiological evidence indicated that difference in the local and tissue-specific photosynthetic activity in the silique wall (a maternal tissue) was responsible for the different seed oil contents. This effect was mimicked by in planta manipulation of silique wall photosynthesis. Furthermore, the starch content and expression of the important lipid synthesis regulatory gene WRINKLED1 in developing seeds were linked with silique wall photosynthetic activity. 454 pyrosequencing was performed to explore the possible molecular mechanism for the difference in silique wall photosynthesis between zy036 and 51070. Interestingly, the results suggested that photosynthesis-related genes were over-represented in both total silique wall expressed genes and genes that were differentially expressed between genotypes. A potential regulatory mechanism for elevated photosynthesis in the zy036 silique wall is proposed on the basis of knowledge from Arabidopsis. Differentially expressed ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-related genes were used for further investigations. Oil content correlated closely with BnRBCS1A expression levels and Rubisco activities in the silique wall, but not in the leaf. Taken together, our results highlight an important role of silique wall photosynthesis in the regulation of seed oil content in terms of maternal effects.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-313X.2011.04802.x

Maternal control of seed oil content in Brassica napus: the role of silique wall photosynthesis

The use of kinetic equations of NO3- transport systems in oilseed rape (Brassica napus), determined by 15NO(3) labeling under controlled conditions, combined with experimental field data from the INRA-Chalons rape database were used to model NO3- uptake during the plant growth cycle. The quantitative effects of different factors such as day/night cycle, ontogenetic stages, root temperature, photosynthetically active radiation, and soil nitrate availability on different components of the constitutive high-affinity transport systems, constitutive low-affinity transport systems, inducible low-affinity transport systems, and inducible high-affinity transport systems of nitrate were then determined to improve the model's predictions. Simulated uptake correlated well with measured values of nitrogen (N) uptake under field conditions for all N fertilization rates tested. Model outputs showed that the high-affinity transport system accounted for about 89% of total NO3- uptake (18% and 71% for constitutive high-affinity transport systems and inducible high-affinity transport systems, respectively) when no fertilizer was applied. The low-affinity transport system accounted for a minor proportion of total N uptake, and its activity was restricted to the early phase of the growth cycle. However, N fertilization in spring increased the duration of its contribution to total N uptake. Overall, data show that this mechanistic and environmentally regulated approach is a powerful means to simulate total N uptake in the field with the advantage of taking both physiologically regulated processes at the overall plant level and specific nitrate transport system characteristics into account.

Modeling Nitrogen Uptake in Oilseed Rape cv Capitol during a Growth Cycle Using Influx Kinetics of Root Nitrate Transport Systems and Field Experimental Data

The effects of drought and nitrogen on growth of winter oilseed rape were investigated during 1991–93 on a coarse sandy soil. Drought in the flowering phase or in the pod-filling phase or throughout the seasons was partly combined with three nitrogen levels of 200, 100 and 0 kg N ha−1. During the dry years 1992 and 1993, at 200 kg N ha−1, seed yield, pod number and seeds per pod were strongly decreased by drought, whereas the seed weight increased after drought during flowering. The straw yield was less affected by drought. Lower nitrogen levels reduced seed yield in the fully irrigated treatments; in the unirrigated treatments, however, the yield was slightly higher at the 0 N and 100 N level than at 200 N in both 1992 and 1993. Nitrogen and drought increased the nitrogen concentration of the seeds and decreased the oil concentration. The interception of photosynthetically active radiation (PAR) was estimated from spectral reflectance ratio measurements. The dry-matter: radiation quotient (∊t) f...

The Effects of Drought and Nitrogen on Light Interception, Growth and Yield of Winter Oilseed Rape

The roles of leaves, stems and reproductive parts in 14CO2 fixation and its subsequent movement in winter oil-seed rape, cultivar Jet Neuf, were investigated in two field experiments carried out on the Wye College Farm. The relative importance of these organs changed with time. At early flowering the leaves were the most important photosynthetic organs (66·8% 14CO2 activity). Midway between flowering and maturity the stems became the major supplier of photosynthates, a role eventually taken over by the developing siliquae (pods).These data stress the importance of keeping all photosynthetically active surfaces free from disease if efficient resource utilization and higher yields are to be achieved.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0021859600041423

Field studies on 14C assimilate fixation and movement in oil-seed rape (B. napus)

Effect of nitrogen on the development of spring oilseed rape.

12 – THE INFLUENCE OF PLANT GROWTH REGULATORS ON THE GROWTH, DEVELOPMENT AND YIELD OF OILSEED RAPE (Brassica napus L.)

The objective of this study was to examine the effect of the chemical growth regulator Terpal (a mixture of mepiquat chloride and ethephon or 2 chloroethyl phosphonic acid) on the pattern of branching, plant height and yield components of winter oil-seed rape (cv. Jet Neuf). Mepiquat chloride (a quaternary ammonium compound with similar antigibberellin properties to cycocel) was developed as a morphoregulator for cotton where it has been shown to reduce plant height, shorten internodes and increase boll retention (Willard et al. 1977). The activity of ethephon has been attributed to its release of ethylene which influences a wide range of developmental processes, for example fruit abscission and ripening (Chatterjee, 1977; Gvozdenovic, Dulic & Slavic, 1978), growth retardation (Van Andel & Verkerke, 1978) and also the extent of lodging in cereals (Hill, Joice & Squires, 1982).

J. F. Chapman

Papers

Field studies on 14C assimilate fixation and movement in oil-seed rape (B. napus)

Effect of nitrogen on the development of spring oilseed rape.

12 – THE INFLUENCE OF PLANT GROWTH REGULATORS ON THE GROWTH, DEVELOPMENT AND YIELD OF OILSEED RAPE (Brassica napus L.)

The effect of Terpal on the yield and yield components of oil-seed rape ( Brassica napus L.)

Towards a ten-tonne crop of rapeseed.