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- When certain indica-japonica differentiation between parents exists, the percentage of combinations with positive heterosis and the mean heterosis of hybrids was high. 利用籼粳分化存在一定差异的亲本杂交，易得到正向优势组合，平均杂种优势较强；
- Furthermore, the F1 hybrids of D5 when crossed to both indica and japonica varieties showed strong positive heterosis in yield characters but negative heterosis in plant height. 目D5与籼、粳品系测交在产量性状上均表现出较强的杂种优势，而株高较矮，具有负向超亲优势。
- It does not mean that a great difference of parents will lead to stronger hetesosis in hybrids and a much great difference in parents seldom bring positive heterotic hybrids. 但并非双亲籼粳分化差异越大越好，双亲差异过大则不易获得正向优势组合，使杂种优势减弱，甚至为负。
- There is positive proof that he did it. 有确切的证据证明他做了此事。
- Her behaviour was a positive outrage. 她的行为残暴到了极点。
- I'm positive she told us to meet at noon. 我肯定她是告诉我们在中午见面。
- This charge is a positive charge. 这个电荷是正电荷。
- She shows a very positive attitude to her work. 她工作态度非常积极。
- Can you be positive about what you hear? 你对听到的话有把握吗？
- He has a positive attitude towards life. 他对生活持有积极的态度。
- The number of positive numbers is infinite. 正数的数目是无穷的。
- positive heterosis 正优势
- Are you positive that you saw him? 你肯定你看到他吗?
- He was positive that he had seen it in the newspaper. 他肯定他已在报纸上看见过。
- There have been positive developments in international relations. 国际关系已逐步改善。
- She was quite positive about the amount of money involved. 她对所涉及的钱数十分肯定。
- The positive or negative character of a proposition. 命题的性质命题的肯定或否定的性质
- We should now call all positive factors into full play. 现在我们应该充分利用一切有利因素。
- We should now bring all positive factors into full play. 现在我们应该充分利用一切有利因素。
- Are you absolutely positive that it was after midnight? 你是否有绝对把握认为那事是在午夜以後发生的?
