求翻译：因此，如何将水稻苗期耐盐性与生殖生长期抗旱性结合起来，培育不同时期耐盐和抗旱的品种是水稻抗逆育种的重要课题。是什么意思？

Therefore, how the reproductive stage and salt tolerance of rice seedling drought resistance combining cultivation in different stages of salt-tolerant and drought-resistant varieties of rice breeding for resistance is an important issue.