Progressive drought alters architectural and anatomical traits of rice roots

Rice

Table 2 Analysis of variance for effects of cultivar and drought treatment on shoot and root traits

	Cultivar	Treatment	Cultivar x Treatment
Growth traits
Shoot dry biomass	0.99	265.02**	23.35**
Tiller number	15.35**	60.84**	20.56**
Root dry biomass	44.80**	770.00**	41.40**
Root/shoot dry biomass ratio	29.51**	209.95**	10.11**
Root architectural traits
Maximum root depth	1.16	474.88**	1.14
Nodal root number	3.69*	63.78**	2.89
Basal large lateral root branching density	0.20	12.68**	0.46
Basal small lateral root branching density	15**	10.11**	18.38**
Apical large lateral root branching density	2.66	201.42**	3.74*
Apical small lateral root branching density	6.59**	3.053	6.138**
Apical large lateral root length	1.78	40.28**	1.22
Apical small lateral root length	11.76**	74.06**	12.05**
Root anatomical traits
Basal cross section area	10.02**	83.38**	5.84**
Basal stele area	2.31	0.16	6.28**
Ratio of basal cross-section to stele areas	12.46**	491.60**	10.85**
Basal median metaxylem vessel area	4.38*	0.29	1.33
Basal metaxylem vessel number	5.83**	12.50**	16.50**
Apical cross section area	10.02**	83.38**	5.84**
Apical stele area	3.09	8.08	0.97
Ratio of apical cross section to stele area	21.47**	322.40**	10.92**
Apical median metaxylem vessel area	1.88	5.67*	0.10
Apical metaxylem vessel number	5.86**	7.00*	3.57*