Root Morphology and Interrelationship between Shoot and Root Growth of a Short-root Near Isogenic Line IL-srt1 Derived from Rice Cultivar Oochikara

• Published in: Root Research Vol. 14; no. 4; pp. 157 - 164
• Main Authors: ZHAO, Rengui, LIU, Jian, SHIOTSU, Fumitaka, TOYOTA, Masanori, KUSUTANI, Akihito, TAKETA, Shin, ICHII, Masahiko
• Format: Journal Article
• Language: English
• Published: Japanese Society for Root Research 2005
• Subjects: Near isogenic line; Rice; Root system; Shoot-root; Short-root
• ISSN: 0919-2182; 1880-7186
• DOI: 10.3117/rootres.14.157

The growth and morphology of IL-srt1, a short-root near isogenic line derived from rice cultivar Oochikara, were characterized by paddy field and pot experiments, with particular focus on the interrelationship between shoot and root growth. The shoot dry weight, stem number, root length and root dry weight per hill of IL-srt1 were lower than those of Oochikara, but the number of crown roots per hill was the same for two cultivars (line). The root weight/root length ratio of IL-srt1 was higher than that of Oochikara, which was attributed to the difference of the mean root diameter, not to the specific gravity of roots. Root system surveys by monolith method revealed that IL-srt1 had smaller root length density at everywhere in soil, and narrow rooting zone. The number of stem per hill was responsible for the difference of shoot dry weight per hill, and there was no difference in shoot dry weight per stem. It was assumed that larger number of crown roots and higher percentage of young crown roots of IL-srt1 as compared to Oochikara might compensate for shorter root length per stem, and attained the same water and nutrient supply per stem. It was also assumed that the rooting zone would closely relate to the emergence and survival of tillers through the ability of water and nutrient supply.