A Quantitative Trait Locus for Chlorophyll Content and its Association with Leaf Photosynthesis in Rice

Abstract

Leaf photosynthesis, an important determinant of yield potential in rice, can be estimated from measurements of chlorophyll content. We searched for quantitative trait loci (QTLs) for Soil and Plant Analyzer Development (SPAD) value, an index of leaf chlorophyll content, and assessed their association with leaf photosynthesis. QTL analysis derived from a cross between japonica cultivar Sasanishiki and high-yielding indica cultivar Habataki detected a QTL for SPAD value on chromosome 4. This QTL explained 31% of the total phenotypic variance, and the Habataki allele increased the SPAD value. Chromosomal segment substitution line (CSSL) with the corresponding segment from Habataki had a higher leaf photosynthetic rate and SPAD value than Sasanishiki, suggesting an association between SPAD value and leaf photosynthesis. The CSSL also had a lower specific leaf area (SLA) than Sasanishiki, reflecting its thicker leaves. Substitution mapping under Sasanishiki genetic background demonstrated that QTLs for SPAD value and SLA were co-localized in the 1,798-kb interval. The results suggest that the phenotypes for SPAD value and SLA are controlled by a single locus or two tightly linked loci, and may play an important role in increasing leaf photosynthesis by increasing chlorophyll content or leaf thickness, or both.

【Short Report】Identification of Chromosome Regions Affecting Leaf Area with Rice Chromosome Segment Substitution Lines

“…The photosynthate produced by a flag leaf is the main source of rice (Cock and Yoshida, 1972;Ishimaru et al, 2007;Takai et al, 2010). Its ability is mainly determined by leaf area, photosynthetic ability per leaf area and light intercepting characters (Kuroda and Kumura, 1990;Mae, 1997).…”

Alleles Affecting 30 Traits for Productivity in Two Japonica Rice Varieties, Koshihikari and Nipponbare (Oryza sativaL.)

“…An increase in tiller number (equal to panicle number) led to an increase in leaf area per plant via higher its number (Peng et al, 2008). Source ability after heading is mainly photosynthate production by flag leaves (Cock and Yoshida, 1972;Ishimaru et al, 2007;Takai et al, 2010), and this production is determined by leaf area and nitrogen content per area (Mae, 1997;Ohsumi et al, 2007;Ujiie et al, 2012). Nitrogen content per leaf area is closely related to photosynthetic rate, and SPAD value is used as an indicator (Peng et al, 1995;Ida, 2006).…”

“…The sink size of plant is represented by panicle number, grain number per panicle, and grain weight (Nagata et al, 2002). The production of photosynthate in a flag leaf is the main source (Cock and Yoshida, 1972;Ishimaru et al, 2007;Takai et al, 2010) and is largely dependent on the leaf area and nitrogen content per area (Mae, 1997;Ohsumi et al, 2007;Ujiie et al, 2012). The chlorophyll meter (SPAD) value has been used as an indicator of nitrogen content (Peng et al, 1995;Ida, 2006).…”

“…For the majority of them, indica varieties have been crossed with japonica varieties (Wan et al, 2004;Ebitani et al, 2005;Takai et al, 2007;Suralta et al, 2008). Using these materials, much genetic information on productivity has been stocked (e.g., Li et al, 1997;Ishimaru et al, 2001;Yue et al, 2006;Madoka et al, 2008;Takai et al, 2010;Ujiie et al, 2012;Ujiie and Ishimaru, 2013).…”

Fine mapping a major QTL qFCC7 L for chlorophyll content in rice (Oryza sativa L.) cv. PA64s

“…These QTLs were distributed on chromosomes 1, 4, 5, 6, 7, 8, and 12, with LOD scores between 2.51 and 9.46 and accounted for 6.0-20.8 % of the total al. 2008; Takai et al 2010). Three randomly selected plants from the middle of a row in each rice line were tested.…”