The physiological genetic effects of 1BL/1RS translocated chromosome in "stay green" wheat cultivar CN17

Abstract

. 2009. The physiological genetic effects of 1BL/ 1RS translocated chromosome in ''stay green'' wheat cultivar CN17. Can. J. Plant Sci. 89: 1Á10. Rye (Secale cereale L.) chromosome arm 1RS in the wheat (Triticum aestivum L.) genetic background has potential significance for yield improvement without affecting its resistance to several diseases. A new wheat cultivar, Chuannong17 (CN17), carrying the wheat-rye 1BL/1RS translocated chromosome, exhibited ''stay green'' phenotypes. To determine the genetic behavior and physiological effect, MY11, CN17, BC 1 F 1 , and F 2 populations of MY11/CN17 were grown in the normal wheat growing seasons in 2004Á2005 and 2005Á2006. Analysis of photosynthetic parameters showed that the coordinate increase of net photosynthetic rate (P n ), stomatal conductance (G s ) and flag leaf area duration from anthesis to maturation (D 2 ) would be the physiological basis of the high yield potential of the 1BL/1RS translocation (CN17). The analysis for morphological indices proposed that the smaller leaf length (L l ), flag leaf width (L w ) and angle between stem and flag leaf (A) would be responsible for the morphological basis of the high yield potential. Analysis of the relationship between the yield and physiological indices suggested that the coordinate increase of source, the partitioning of assimilate from source to sink, and the sink strength was the material basis of the high yield potential. These results afforded some persuasive evidence to support the idea that wheat cultivar CN17 also shows a coordinate relationship between physiology and morphology and is indeed functionally a ''stay green'' cultivar. The results show that exploitation of a foreign chromosome or chromosome arm such as 1RS to develop ''stay green'' genotype cultivars in wheat breeding has the potential to increase yield.Key words: 1BL/1RS translocated chromosome, photosynthesis, physiological genetic effect, stay green, wheat Luo, P. G., Zhang, H. Y., Shu, K., Wu, X. H., Zhang, H. Q. and Ren, Z. L. 2009. Incidence physiologique et ge´ne´tique de la translocation du chromosome 1BL/1RS chez le cultivar « toujours vert » de ble´CN17. Can. J. Plant Sci. 89: 1Á10. La pre´sence du bras du chromosome 1RS du seigle (Secale cereale L.) dans le ge´nome du ble´(Triticum aestivum L.) pourrait avoir une certaine importance en ame´liorant le rendement de cette culture sans affecter sa re´sistance a`plusieurs maladies. Le nouveau cultivar de ble´Chuannong17 (CN17), chez qui le chromosome ble´-seigle 1BL/1RS a e´te´transfe´re´par translocation, exprime le phe´notype « toujours vert ». Pour ve´rifier le comportement ge´ne´tique et les effets physiologiques de la manipulation, les auteurs ont cultive´les populations MY11, CN17, BC 1 F 1 et F 2 de MY11/CN17 durant la saison de croissance normale du ble´, en 2004Á2005 et 2005Á2006. L'analyse des parame`tres photosynthe´tiques indique qu'un rele`vement coordonne´du taux de photosynthe`se net (P n ), de la conductance des stomates (G s ) et de la surface de la feuille paniculaire en...

Physiological characterization of ‘stay green’ wheat cultivars during the grain filling stage under field growing conditions

“…Such findings have been reported in durum and wheat (Rampino et al 2006;Luo et al , 2009. Two wheat cultivars, CN12 and CN18, with the wheat-rye 1BL/ 1RS translocation (Tang et al 2008) that were released into southwest China in 2003 exhibit a similar stay-green phenotype to that of CN17 (Luo et al 2009), the sister line of both CN12 and CN18 (Luo et al 2008;Tang et al 2008).…”

“…Wheat (Triticum aestivum L.) is one of the most important crops, and its yield potential has significantly improved, increasing above the global biomass (Reynolds et al 2000). However, the maintenance of longer photosynthetic competence is one of the most effective ways to increase wheat biomass yield and yield potential Luo et al , 2009, especially after flowering in the flag leaf, from which most accumulated wheat assimilates in grains mainly come (Austin et al 1977;Sylvester-Bradley et al 1990). Therefore, improving the photosynthetic competence of the flag leaf could play a potentially significant role in increasing wheat yield.…”

Photosynthesis and Leaf Senescence as Determinants of Plant Productivity

“…However, increases in radiation use efficiency obtained by genetic manipulation of the senescence programme should be accompanied by other adaptations in the whole-plant physiology. Stay-green phenotypes that have a sustained long period of high photosynthetic capacity could increase grain numbers per area as well as result in a greater number of stronger sinks that would again enhance photosynthetic rates (Luo et al 2009). Some staygreen wheat cultivars have larger grains (Chen et al 2010).…”

In silico cloning and chromosomal localization of EST sequences that are related to leaf senescence using nulli-tetrasomes in wheat

“…Three wheat cultivars, CN12, CN17, and CN18, were developed from the progenies of a wheatrye wide cross and are sister lines with a wheat-rye 1BL/1RS translocation (Tang et al 2008). Many regions in southwest China grow these cultivars because of their high yield (Luo et al 2009) and good resistance to diseases, including stripe rust (Luo et al 2008) and powdery mildew ). Previous studies have demonstrated that CN12, CN17, and CN18 are functional stay-green varieties that maintain high photosynthetic competence during the grain-filling stage (Luo et al 2006) and are associated with a high yield (Luo et al 2009).…”

“…Many regions in southwest China grow these cultivars because of their high yield (Luo et al 2009) and good resistance to diseases, including stripe rust (Luo et al 2008) and powdery mildew ). Previous studies have demonstrated that CN12, CN17, and CN18 are functional stay-green varieties that maintain high photosynthetic competence during the grain-filling stage (Luo et al 2006) and are associated with a high yield (Luo et al 2009). A complete understanding of the underlying molecular mechanism and genetic basis, particularly which genes or chromosome regions are crucial in controlling these traits, is notably important for further use of the varieties in wheat yield improvement.…”