Endophytic microorganisms and nitrogen levels on rice plant growth

Gois, Larissa de Souza; Santos, Jessica Silva; Santos, Jacilene Francisca Souza; Barbosa, Andrea Verônica Gobbi; Viégas, Pedro Roberto Almeida; Marino, Regina Helena

ABSTRACT

Endophytic microorganisms can stimulate growth depending on the interaction between the host plant and soil nutrients availability. This work aimed to evaluate the growth of rice BRS Tropical plants cultivated with endophytic microorganisms and nitrogen levels in greenhouse. The experimental design was 4 x 4 factorial scheme completely randomized, corresponding to four treatments (control - without fungal inoculum and three mycorrhizal isolates: UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum and UFLA401 - Acaulospora morrowiae) and four doses of urea (0, 100, 300 and 600 mg Kg^-1 N), with four replications. Rice BRS Tropical plants were colonized by arbuscular mycorrhizal fungi (AMF) and endophytic fungi dark septate (DSE). Nitrogen fertilization based on urea does not influenced colonization by UFLAs and by endophytic fungi DSE in rice plants. Nitrogen fertilization inhibited the formation of hyphae, but does not the production of vesicles and arbuscules of the UFLAs isolates. Mycorrhizal sporulation was inhibited by nitrogen fertilization, depending on the fungi isolate. The control treatment rice plants colonization by endophytic fungi DSE, without AMF, was inhibited by nitrogen fertilization. The colonization by endophytic fungi DSE do not interfered in the mycorrhizal colonization by UFLA isolates. Rice BRS Tropical plants were responsive to the inoculation of isolates UFLA351 and UFLA401 with 600 mg Kg^-1 N. Rice BRS Tropical plants cultivated without AMF and with 600 mg Kg^-1 N were responsive to nitrogen fertilization.

Index terms:
Symbiosis; nitrogen fertilization; microbial interaction.

[1] ^*Corresponding author: rehmarino@hotmail.com

Trat.	N (mg Kg^-1)	MC (%)	HYP (%)	VES (%)	ARB (%)	ARB: VES	NS	DSE (%)
Control	0	0.0a	0.0a	0.0a	0.0a	0.00a	256.8a	261.1a
	100	10.7a	16.7a	1.7a	1.7a	0.25a	220.8ab	107.2b
	300	0.0a	0.0a	0.0a	0.0a	0.00a	255.8ab	25.1b
	600	0.0a	0.0a	0.0a	0.0a	0.00a	106.3b	23.9b
	Equation R²	Linear 0.18 ns	Linear 0.18 ns	Linear 0.18 ns	Linear 0.18 ns	Linear 0,14 ns	Linear 0.70*	Linear 0.65 ns
UFLA351	0	34.0a	87.2a	12.8a	9.1a	0.43a	174.5a	2.4a
	100	60.9a	37.6b	13.9a	9.2a	0.42a	128.5a	13.4a
	300	48.2a	35.4b	12.8a	16.5a	1.17a	168.3a	31.8a
	600	50.0a	23.9b	23.2a	18.3a	0.41a	137.0a	2.1a
	Equation R²	Linear 0,28 ns	Linear 0.60**	Linear 0.75 ns	Linear 0.87 ns	Linear 0.01 ns	Linear 0.14 ns	Linear 0.01 ns
UFLA372	0	49.4a	43.6ab	1.2a	3.5a	0.25a	161.8a	23.6a
	100	20.8a	76.7a	16.7a	8.4a	0.50a	244.5a	6.6a
	300	22.3a	19.2b	5.8a	1.9a	0.08a	192.3a	29.0a
	600	23.1a	42.2ab	12.9a	8.6a	0.17a	156.0a	14.6a
	Equation R²	Linear 0,33 ns	Linear 0,21 ns	Linear 0.14 ns	Linear 0.29 ns	Linear 0.27 ns	Linear 0.47 ns	Linear 0.08 ns
UFLA401	0	35.0a	82.4a	36.0a	48.5a	0.78a	285.5a	54.1a
	100	30.6a	100.8a	19.2a	21.6a	0.30a	95.5b	3.9a
	300	50.3a	76.9a	44.7a	29.2a	0.51a	123.0b	6.2a
	600	18.8a	1.7b	23.3a	10.0a	0.11a	132.0b	1.7a
	Equation R²	Linear 0.7 ns	Quadratic 0.99 **	Linear 0.21 ns	Linear 0.66 ns	Linear 0.59 ns	Linear 0.62 *	Linear 0.44 ns

Treatments	N (mg kg^-1)	PH (cm)	DSM (g)	RL (cm)	DRM (g)	DSM/ DRM
Control	0	45.2a	0.33a	11.7a	0.16a	2.0a
	100	30.5a	0.15a	12.1a	0.15a	1.3a
	300	33.8a	0.23a	15.2a	0.14a	1.6a
	600	39.4a	0.45a	13.3a	0.35a	1.5a
	Equation R²	Linear 0.01 ns	Linear 0.41 ns	Linear 0.29 ns	Linear 0.71 ns	Linear 0.16 ns
UFLA351	0	36.8a	0.29a	11.6b	0.13a	2.3a
	100	36.2a	0.28a	12.6b	0.22a	1.5a
	300	40.3a	0.30a	19.6a	0.19a	2.3a
	600	41.8a	0.35a	13.4b	0.25a	1.4a
	Equation R²	Linear 0.87 ns	Linear 0.86 ns	Linear 0,09 ns	Linear 0.61 ns	Linear 0.27 ns
UFLA372	0	11.0b	0.13a	11.1a	0.06a	3.2a
	100	37.1a	0.26a	15.5a	0.26a	1.1a
	300	33.5a	0.18a	13.5a	0.11a	1.8a
	600	40.2a	0.38a	14.6a	0.26a	1.5a
	Equation R²	Linear 0.50*	Linear 0.66 ns	Linear 0.21 ns	Linear 0.31 ns	Linear 0.21 ns
UFLA401	0	39.7a	0.35a	16.9a	0.17ab	2.4a
	100	37.0a	0.27a	14.3a	0.32ab	3.1a
	300	35.7a	0.24a	13.0a	0.10b	3.0a
	600	46.7a	0.48a	12.4a	0.43a	1.1a
	Equation R²	Linear 0.47 ns	Linear 0.37 ns	Linear 0.75*	Linear 0.31 ns	Linear 0,51 ns

Brasil

Brasil

Endophytic microorganisms and nitrogen levels on rice plant growth

ABSTRACT