Enhancement of NSIC Rc 192 Seedling Growth by Soil-based and Carbonized Rice Hull (CRH)-based  Actinomycete Inoculants

Kassandra Jin B. Mariano; Ann Jhudeil C. Santos; Editha V. Evangelista; Jayvee A. Cruz

Kassandra Jin B. Mariano Department of Biological Sciences Central Luzon State University Science City of Muñoz, Nueva Ecija 3120 Philippines
Ann Jhudeil C. Santos Agronomy, Soils, and Plant Physiology Division Philippine Rice Research Institute Science City of Muñoz, Nueva Ecija 3120 Philippines
Editha V. Evangelista Agronomy, Soils, and Plant Physiology Division Philippine Rice Research Institute Science City of Muñoz, Nueva Ecija 3120 Philippines
Jayvee A. Cruz Agronomy, Soils, and Plant Physiology Division Philippine Rice Research Institute Science City of Muñoz, Nueva Ecija 3120 Philippines

Keywords: actinomycetes, inoculant carrier, plant growth-promoting bacteria (PGPB), rice, seed germination

Abstract

A study was conducted to observe the effects of soil-based (SB) and carbonized rice hull (CRH)-based actinomycete inoculants on the seedling growth of rice variety NSIC Rc 192. The experiment was conducted under laboratory conditions using wet paper towels in petri dishes. The statistical design of the experiment was completely randomized (CRD) with three replicates per treatment. The actinomycete isolate, Streptomyces sp., used in the study was previously reported to produce indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and phosphatase. In this experiment, rice seeds were treated with soil-based and CRH-based actinomycete inoculants. Growth parameters such as shoot and root length and oven dry weight were measured 7 days after sowing (DAS). Inoculation with CRH-based and soil-based actinomycete inoculants significantly increased shoot length by 102.61% and 94.77%, respectively, relative to the uninoculated treatment at 7 DAS. Inoculation with CRH-based and soil-based actinomycete inoculants significantly increased root length by 113.24% and 98.53%, respectively, relative to the uninoculated treatment at 7 DAS. The highest shoot (4.5 mg) and root (3.5 mg) oven dry weight was observed at CRH-based inoculation while the lowest shoot (2.0 mg) and root (0.5 mg) was obtained at the uninoculated control. Regardless of the carrier used, actinomycete isolate can enhance the growth of rice seedlings. Both CRH and soil-based actinomycete inoculants significantly increased the shoot and root length and oven dry weight of rice seedlings.