Rooting ability and water relations of rice plant

Under low evaporative demand conditions profuse nodal root production (14 to 17 roots per node) was achieved in mature excised rice (Oryza sativa L.) stem standing with its one basal node under water for 2 weeks in the laboratory. Intact panicle was greatly inhibitory to nodal root production whereas leaves were stimulatory to it. The entire length of new and young roots contributed to water absorption and trAnSport to the shoot with apical portions being more active in this phenomenon. Pruning of old roots facilitated rapid production of new ones which helped raise plant water status from −12.5 bars to −4 bars following seedling uprooting from nursery beds. Leaf pruning was not conducive to root production. Surprisingly, uprooted seedlings with their entire root and leaf systems intact exhibited the lowest leaf water potential (−10 bars) after 2 weeks. The relevance and significance of new roots in water absorption and seedling establishment during post transplanting period have been discussed.