New insights into the phenology, genetics and breeding system of critically endangered Nardostachys grandiflora DC

Figures & data

Figure 1. N. grandiflora (a) plant; (b) rhizome; (c) inflorescence.

Figure 2. N. grandiflora (a) transverse section of ovary; (b) capitate stigma; (c) trilobed stigma; (d) stomata.

Table 1. Some leaf (radical) constants of N. grandiflora.

Feature	Observation
Palisade ratio	6.47 ± 0.35
Vein-islet number	1.77 ± 0.16 per mm^2
Vein termination number	1.35 ± 0.16 per mm^2
Type of stomata	Anomocytic (Figure 2d)
Size of stomata (mm)	0.02 ± 0.001 × 0.035 ± 0.001
Stomatal index	22.24 ± 1.06

Table 2. Qualitative and quantitative features of N. grandiflora.

Plant part	Qualitative	Quantitative
Stem	Erect, represented by flowering shoot.	Up to 20.55 ± 2.28 cm (height)
Rootstock	Perennial rhizomatous with adventitious roots.	L: 6.9 ± 0.41cm
		B: 6.35± 0.5 mm
Leaves
Radical	Rosette arrangement, petiolated, simple, estipulate, lanceolate, lamina entire with acute tip and attenuated base.	L: 11.9 ± 0.56 cm
		B: 1.85 ± 0.13 cm
Cauline	Paired, opposite, sessile, simple, estipulate, ovate, lamina entire, acute tip and attenuated base showing decurrent attachment.	L: 4.28 ± 0.22 cm
		B: 1.07 ± 0.11 cm
Inflorescence	Dichasial cyme with condensed cyme heads.	Length of flowering shoot: 20.55 ± 2.28cm
		No. of flowering shoots/plant: 1
Flower	Bracteate, actinomorphic (or irregular), bisexual, complete, epigynous.	L: 10.8± 0.20 mm
		B: 3.3± 0.18 mm
Calyx	Gamosepalous with five dentate lobes which are green in centre and purplish towards margin. Odd sepal posterior.	Lobe size: 1.5–2 mm
Corolla	Petals fused below forming tube with five lobes above, campanulate, odd petal anterior and purplish with pink tinge.	L:
		Total: 7.9 ± 0.12 mm
		Fused: 4.9± 0.06 mm
		B: 3.3 ± 0.18 mm
Androecium	Four stamens, haplostamenous, epipetalous, oppositipetalous. Anthers dorsifixed, kidney shaped with two violet colored anther lobes. Staminode present in some flowers.	Filament length: 8.79 ± 0.19 mm
		Anther size: 2.1± 0.09 × 1.3± 0.12 mm
Gynoecium	Tricarpillary syncarpous, trilocular with single fertile anatropous ovule in one locule showing apical placentation and the rest empty. Style linear and papillate stigma trilobed or capitate.	Ovary
		L: 2.11 ± 0.05
		B: 1.94 ± 0.05 mm
		Style
		L: 9.3 ± 0.28 mm
		Stigma: 0.4 × 0.31 mm
		Ovule size: 0.47 × 0.36 mm
Fruit/seed	Achene	L: 4.3 ± 0.18
	Pale brownish colored.
		B: 2.1 ± 0.05 mm
		100 fruit/seed weight: 0.389 gm

Abbreviations: L, length; B, breadth.

Table 3. Pheno-phases of N. grandiflora.

Pheno-phases	Time of year
Re-sprouting	May onwards
Development of inflorescence	June onwards
Flowering	June–August
Peak flowering	Mid July to first week of August
Fruit formation	August onwards
Seed ripening and dispersal	September–October
Perennation	Mid October to May

Figure 3. N. grandiflora (a) anther dehiscence; (b) stigma receptive stage.

Figure 4. N. grandiflora (a) metaphase-I; (b) anaphase-I; (c) diagramatic representation of metaphase-I.

Figure 5. N. grandiflora (a) isobilateral tetrad; (b) decusate tetrad; (c) tetrahedral tetrad.

Figure 6. N. grandiflora (a) tricolpate pollen grain; (b) bicolpate pollen grain; (c) tetracolpate pollen grain; (d) pentacolpate pollen grain; (e) all pollen morphs in one anther.

Table 4. Dynamics of different type of pollen grains in the same flower.

Type of pollen grain	Bicolpate	Tricolpate	Tetracolpate	Pentacolpate
Shape	Spherical-oval	Spherical-oval	Spherical-oval	Spherical-oval
No./flower	0–955	4528–6135	0–604	0–48
% stainability	86.38± 0.83	92.12 ± 1.72	97.34 ± 0.85	99.1 ± 0.8
% of pollen grain in flower	0–15.56	73.8–100	0–9.84	0–0.74
Length (mm)	0.075 ± 0.002(0.06–0.09)	0.062 ± 0.03(0.06–0.07)	0.074 ± 0.004(0.05–0.11)	0.090 ± 0.001(0.08–0.098)
Breadth (mm)	0.054 ± 0.001(0.05–0.06)	0.062 ± 0.001(0.05–0.07)	0.074 ± 0.004(0.05–0.11)	0.090 ± 0.001(0.08–0.094)

Values in parenthesis are ranges.

Table 5. Effect of different pollination methods on fruit set, seed set and seed germination in N. grandiflora.

Treatment	Fruit set (%)*	Seed set (%)*	Seed germination (%) **
Open pollination	18.94 ± 0.18	8.08 ± 0.16	71.64 ± 0.42
Autogamy	4.52 ± 0.24	1.85 ± 0.17	71.09 ± 0.30
T calculated value	53.63	29.28	1.21

^* Out of total number of flowers studied

^** Out of total seed set