科研之友
微信
新浪微博
Facebook
分享链接
摘要
The modern wheat cultivars have been selected for non-limiting nitrogen (N) input situations and therefore require large amounts of fertiliser N. The relatively high price of fossil fuels increases the cost of N fertilisers, putting pressure on wheat farmers. Doubled-haploid mapping populations can lead to identification of specific loci that might be useful in marker-assisted breeding for increased N-use efficiency. @@@ Forty-one mostly Australian genotypes of wheat (Triticum aestivum L.) (parents of existing doubled-haploid mapping populations) were grown to maturity in soil in a glasshouse. Two N treatments were tested: optimal (685 mg N pot(-1)) and low (171 mg N pot(-1)). @@@ Plant growth was significantly lower in most genotypes (with the exception of Mendos and Gamenya) at low compared with optimal N supply. Leaf-6 extension rate in the low-N treatment was on average 76 % of that in the optimal N treatment. Grain yield was significantly affected by the treatment x genotype interaction, ranging from 2.5 (genotype WAWHT2046) to 7.0 g per plant (genotype Mendos) under low N supply, and from 3.8 (genotype Wilgoyne) to 10.1 g per plant (genotype Lang) under optimal N supply. Based on responses to differential N supply, Mendos and Wilgoyne ranked as N-use efficient. In contrast, ten genotypes (Cadoux, Frame, Gamenya, Halberd, Janz, Lang, Neepawa, Spear, Sunco and Tasman) were ranked as N-use inefficient. The old genotype Gamenya was relatively N-use efficient, but had a poor response to N fertilisation. Amery and Janz responded similarly to Gamenya. @@@ Even though genotypes used in the current study were bred mostly for yield, a range of differential responses to the low- and optimal-N treatments implies that efficient use of N at low supply and efficient response to N fertilisation might have been inadvertently selected for in some breeding programmes, suggesting a potential for breeding wheat cultivars with improved N-use efficiency.
- 出版日期2016-11
