Advances in studies on crop boron nutrition and application of boron fertilizers in China

Boron (B) is one of the essential micronutrients for plant growth and yield construction. After " budding but no flowering” in cotton and " flowering but no seed setting” in rapeseed were confirmed to be B-deficient symptom in China from 60s to 70s last century, the studies on B nutrition and application of B fertilizers in crops were initiated, and a series of great achievements were made during the past 50 years. In this article, we reviewed the achievements made by Chinese scientists focusing on the field research, including B nutrition diagnose and application of B fertilizers in crops, uptake and utilization of B, physiological function of B, genetic and molecular mechanism of B nutrition in crops. It has confirmed that different crop species show significant differences in B demand and B-deficient response. B nutrition characterization in plants, critical index and diagnosis methods for B nutrition in plants and soils, and techniques and standards of B fertilizer application were established. Genotype difference in B use efficiency and its genetic law were revealed in Brassica napus and cotton, as well as the genes for B transporters and their functions. In future, more work should be done in the accurate and early diagnosis of B nutrition in plants, and the synergistic effect of B and other essential nutrients for servicing the modern agricultural industry. The biological mechanism of B nutrition efficiency of crops should be focused on the goal breeding new varieties with high yield and good quality and high B efficiency, to make contribution to the sustainable development of agriculture in China.