Studies on Root System Formation in Leguminous Crop Plants : 5. On the root system of peanut plants

• Published in: Japanese Journal of Crop Science Vol. 37; no. 4; pp. 656 - 661
• Main Authors: TANAKA, Noriyuki, FUJII, Yoshihiro, SOEJIMA, Masuo
• Format: Journal Article
• Language: English
• Published: CROP SCIENCE SOCIETY OF JAPAN 1968
• ISSN: 0011-1848; 1349-0990
• DOI: 10.1626/jcs.37.656

1. The root systems of peanuts were consist of numerous lateral roots derived from the main root weighed more than 95 percent of the total roots. Adventitious roots derived from hypocotyl and ramifications were quite few in number and poor in growth. 2. The primary branch roots emerged densely from the part near to the base of the main root, but they decreased gradually as nearer to the root apex. 3. The primary, secondary and tertiary branch roots were generally observed, while the fourth and subsquent ones were rarely. 4. The secondary and tertiary branch roots were so short in length that they were not so much complicated, and seemed that it facilitated the gynophors to push into soil and the pegs to grow. 5. With regard to the emergence of hypocotyl roots, varietal differences were recognized. Namely, in cases of Spanish and Valencia types, the emergence of roots from hypocotyl was very difficult, while in the cases of Virginia and Southeast Runner types, it seemed somewhat easy. 6. It was considered that such meager root system was closely related to the differenciation of the cortex of the hypocotyl, particularly of cortex cells, as well as to the growth of hypocotyl roots. Accumulation of cell membranes resulting from the collapse of the cortex cells and the formation of cork layer seemed to restrain the development and elongation of the primordial roots. 7. Adventitious roots developed from the ramifications just above the ground were observed at latter growth stage, more in cases of prostrate type varieties. 8. It was proved that the development of such adventitious roots was strongly affected by the moisture-content in the soil. From these results, it can be concluded that the functions of peanut roots are exclusively performed by the main root systems, and the part played by the adventitious roots is quite temporary.