14. Inheritance of two anatomical characteristics

An extra sclerenchymatous band is found in the stem of some special rice varietites but not in others. Two rice varieties FR13A and Intan have such bands. Its occurrence was investigated in four crosses between varieties having the band and those lacking the band (Ratna, Jana, CRM 13 named 'Sattari'). The main stems from five F\1\ and 100 F\2\ plants of each cross were cross-sectioned for observation. All the plants showed the extra band although its continuity as a circular band and its thickness varied among crosses. The F\2\ Populations showed, in terms of the presence or absence, a 9 : 7 ratio indicating that two complementary dominant genes were involved. The mode of variation among plants also suggested segregation for some modifiers. The complementary genes were symbolized Esb\1\ and Esb\2\.

The fuscoid cells are those with big vacuoles occurring on either side of the vascular bundle in the leaf blade. Such cells are commonly found in bamboo but are rather rare in rice. A salt-tolerant variety, Phulbuh, having such cells was crossed CR 1039(M) which lacks such cells. The F\1\ and F\2\ data showed that the occurrence of the fuscoid cells was controlled by a dominant gene, which was symbolized Fc.