26. Stomatal frequency associated with an esterase band in rice genotypes

Jen-Hsien Weng and Ching-Yih Chen

Department of Botany, National Chung Hsing University, Taichung, Taiwan 40227, ROC


In our previous paper (Weng and Chen 1987b) we reported that a recessive gene for high photosynthetic ability was linked with a gene specifying a particular band of esterase (called E1), which was detectable by a special method of assay: electrophoresis with a vertical polyacryamid gel and stain with fast blue RR salt and a-naphthyl acetate in phosphate buffer. This band was distributed in Indica varieties and a few high-yielding Japonicas newly bred in Taiwan. On the other hand, stomatal frequency on the leaves ws found to be higher in Indica than in Japonica varieties (Yoshida and Ono 1978). It may be inferred that th higher stomatal frequency in Indica varieties is a causal factor for their high photosynthetic ability (Weng and Chen 1987a).

In order to elucidate the relationship between the esterase E1 band and stomatal frequency, we have examined two rice varieties, Taichung 65 (T65, Japonica, no E1 band) and Taichung Native 1 (TN1, Indica, with the E1 band), and their F\1\ and F\2\ plants. TN1 had higher stomatal frequency than T65.

The F\1\ plants from T65xTN1 and TN1xT65 showed the E1 band and a stomatal frequency intermediate between the parental values (Table 1). Among the F\2\ plants examined, those without the E1 band generally had higher stomatal frequency than those without the E1 band. This was recognized in both the upper and lower surface of the leaves in parallel (Fig. 1).

Our previous (Weng and Chen 1987b) and present crossing expriments have consistently shown that the esterase band in question is controlled by a dominant gene, which may be symboled Est-10 tentatively. The tendency of stomatal frequency to be higher in F\2\2 plants with this band suggests that Est-10(t) is linked with a gene for stomatal frequency. The linkage of Est- 10(t) with a gene for high photosynthetic ability was reported already (Weng and Chen 1987b). How the gene for stomatal frequency and that for photosynthetic ability are interrelated is left for investigation in the future.


Table 1. Stomatal frequencies (no./mm2) obtained in Taichung Native 1 (TN1), Taichung 65(T65) and their F\1\ plants

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Genotype                   E\1\ band            Upper surface    Lower surface
                                                 (adaxial)        (Abaxial)
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TN1                         +                      362 a            526 a
T65                         -                      324 a            413 b
F\1\: T65XTN1               +                      343 a            462 b
F\1\: TN1XT65               +                      321 a            474 b
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a and b differ at 5% level.
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Fig. 1. Segregation for stomatal frequency in the F\2\ of Taichung 65 x Taichung Native 1 :Plants with and without the E\1\ band are shown by solid and open histograms, respectively.

Above-Adaxial part (upper surface) of leaves;

Below-Abaxial part (lower surface) of leaves.





References

Weng, J.H. and C.Y. Chen, 1987a. Differences between Indica and Japonica rice varieties in CO\2\ exchange rates in response to leaf nitrogen and temperature. Photosynthesis Res. 14: 171-178.

Weng, J.H. and C.Y. Chen, 1987b. Photosynthetic ability associated with an esterase band in rice genotypes. RGN 4: 93-94.

Yoshida, T. and T. Ono, 1978. Environmental differences in leaf stomatal frequency of rice. Jpn. J. Crop Sci. 47: 506-514.