Carbon and Nitrogen Assimilation and Partitioning in Canola (Brassica Napus L.) In Saline Environment

ABSTRACT

Environmental stress strongly affects the fundamental processes of plant biology. This study was to investigate the growth, yield, carbon (C) and nitrogen (N) assimilation and partitioning of two canola (Brassica napus L.) cultivars (Qinyou 10 and Ningza 1838) under low and high soil salt-ion concentration levels (LSSC and HSSC) of 2.512 and 4.722 g kg⁻¹, respectively. There was no cultivar effect on agronomic traits other than the 1000-seed weight which was not affected by soil salinity. The increase of soil salt-ion concentration greatly reduced plant height, the numbers of primary branches, pods per plant or per hectare and the resultant seed yield. The C and N accumulations for whole plant and in different organs decreased significantly as soil salinity increased. The suppressive effects of high soil salinity were more strongly on C accumulation than N accumulation, and more obviously in shells and seeds than in roots, stems and leaves. As soil salinity increased, the C and N partitioning in vegetative organs of roots, stems, and leaves was enhanced greatly, while the C partitioning in shells and seeds and the N partitioning in seeds decreased significantly, suggesting an inhibition of C and N transporting from vegetative organs to reproductive organs. Our study revealed the high soil salinity profoundly suppressed canola growth and yield formation, by reducing C and N accumulations in all organs and alleviating C and N partitioning in reproductive organs.

KEYWORDS:

• Canola
• soil salt-ion concentration
• yield
• C and N
• assimilation and partitioning

Acknowledgments

We thank our lab staff for their help in determination and analysis.

Additional information

Funding

This work was financially supported by the National Key Research and Development Program of China (2018YFD1000900); and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).