Photosynthetic Characteristics And The Mapping Of Related Stay-green Gene Of Super-green Rice Mutant

Changes of chlorophyll content,photosynthetic gas exchange parameters and fluorescence parameters were studied at tillering stage,jointing stage,booting stage, grain-filling stage and mature stage using super-green rice mutant SN 19-6 as material. Genetic action of the super-green character was analyzed by using the F₁ and F₂ progenies from SN19-6 crossed with normal green parent SN12-5.Furthermore,this super-green mutant gene was mapped preliminarily with microsatellite marker.The results are as follows:1.Relative content of chlorophyll SPAD values in super-green rice mutant were significantly and very significantly higher than that in normal green leaves of rice lines in different leaf position at tillering stage,booting stage,heading date,grain-filling stage and mature stage,and chlorophyll a and chlorophyll b content also showed the same trend. Carotenoid content was significantly or very significantly higher in super-green rice mutant than in normal green leaves at the booting stage,heading stage,filling stage and mature stage of rice materials,and normal green leaf materials showed no significant difference in different leaf position.2.The net photosynthetic rate,stomatal conductance and intercellular CO₂ concentration of super-green rice mutant were significantly and very significantly higher than that of the normal green materials at tillering stage,jointing stage,booting stage and mature stage,and the super-green rice mutant had no significant differences compared to the normal green rice in net photosynthetic rate of flag leaves at grain-filling stage,while 2^nd and 3^rd leaves from the top were significantly higher than the normal materials,and the stomatal conductance and intercellular CO₂ concentration were significantly and very significantly higher than CK. Super-green rice mutant was significantly and very significantly higher than CK in transpiration rate.Leaf vapor pressure deficit was no significant difference between super-green rice mutant and normal green leaves of rice materials at tillering stage,and that of super-green rice mutant was significantly and very significantly lower than the normal green leaves of rice materials at the filling stage and mature stage.3.Super-green rice mutant was significantly and very significantly higher than the normal green materials of rice in the maximal fluorescence(Fm),dark adaptation minimum fluorescence(Fo),coefficient of photochemical quenching(Qp),PSII photochemical efficiency(Fv'/Fm'),apparent electron transport(ETR) and the PSII reaction center of the efficiency of excitation energy capture(Fv'/Fm'),but the non-photochemical quenching coefficient(QN) of super-green rice mutant was significantly lower than other three normal materials.4.SPAD values was significantly or very positively correlated with chlorophyll a(Chl a) and chlorophyll b(Chi b) content in different leaf position.There was significant positive correlation between ETR and Chl content.1000-grain weight was significantly or very significantly positively correlated with yield,seed-setting rate and the grains number,while the grains number was negatively correlated with seed-setting rate.5.Three QTLs were detected,which were qCHL8,qCHL1 and qCHL2 at the heading stage and mature stage,and the contribution rate of the first two were 9.59%and 12.49%, respectively.qCHL8 additive effect was positive,indicating that the favorable QTL came from the super-green materials 'Shen Nong 19-6',which could increase the chlorophyll content to 1.7927;and the additive effect qCHL1 was negative,indicating that this locus to a favorable allele from the normal green leaf material 'Shen Nong 12-5',which could increase the chlorophyll content to 1.9658.qCHL2 and qCHL1 showed the genetic effects of additive×additive,which value was 1.0370,while also showed dominance×dominance effects, which value was 2.7573.Test on stay-green showed that QTL qsgll was found on chromosome 1,and additive effect was 0.0513 with the contribution rate of 6.06%.