The pollen morphology of 33 different plant species belonging to 18 families was studied. The high range of variability in pollen characters were observed in the present study (Table 3).
Table 2
Details of the studied plant species
Sl No | Name of the species | Family | Habit | Life Span | Phenology Period | Raunkiaer’s Life Forms | Distribution |
01 | Sphagneticola trilobta (L.) Pruski | Asteraceae | H | P | Aug-Sep | THP | E |
02 | Lilium candidum L. | Liliaceae | S | P | Aug-Sep | HCP | E |
03 | Impatiens balsamina L. | Balsaminaceae | H | A | Aug-Sep | THP | N |
04 | Zephyranthes citrina Baker | Amaryllidaceae | H | P | Aug-Sep | HCP | E |
05 | Benincasa hispida (Thunb.) Cogn. | Cucurbitaceae | H | A | Aug-Oct | HCP | N |
06 | Ageratum conyzoides L. | Asteraceae | H | A | Aug-Dec | THP | E |
07 | Mimosa pudica L. | Fabaceae | H | A | Aug-Nov | CHP | E |
08 | Cucurbita maxima Dushesne | Cucurbitaceae | H | A | Oct-Nov | HCP | E |
09 | Zephyranthes rosea Lindle. | Amaryllidaceae | H | P | Oct-Dec | CHP | E |
10 | Bauhinia variegata L. | Fabaceae | T | P | Oct-Nov | PH | N |
11 | Tradescantia pallida (Rose) D.R.Hunt | Commelinaceae | H | P | Aug-Dec | CHP | E |
12 | Ipomoea cairica (L.) Sweet | Convolvulaceae | H | P | Oct-Dec | HCP | N |
13 | Ipomoea bahiensis Willd. | Convolvulaceae | H | P | Oct-Dec | HCP | E |
14 | Malastoma malabathricum L. | Melastomataceae | S | P | Sep-Nov | HCP | N |
15 | Alternathera sessilis (L.) R.Br. ex DC. | Amaranthaceae | H | P | Aug-Nov | CHP | N |
16 | Luffa aegyptiaca Mill. | Cucurbitaceae | H | A | Aug-Dec | CHP | N |
17 | Mikania micrantha Kunth | Asteraceae | S | P | Sep-Nov | CHP | E |
18 | Averrhoa carambola L. | Oxalidaceae | T | P | Oct-Dec | PH | E |
19 | Ziziphus jujube Mill. | Rhamnaceae | T | P | Oct-Dec | PH | E |
20 | Rosa alba L. | Rosaceae | S | P | Aug-Dec | PH | E |
21 | Jasminum multiflorum (Burm.) Andrews | Oleaceae | S | P | Oct-Dec | PH | N |
22 | Luffa acutangula (L.) Roxb. | Cucurbitaceae | H | P | Aug-Dec | CHP | N |
23 | Hibiscus mutabilis L. | Malvaceae | S | P | Sep-Dec | PH | E |
24 | Hibiscus syriacus L. | Malvaceae | S | P | Sep-Dec | HCP | N |
25 | Acacia auriculiformis A.Cunn.ex Benth | Fabaceae | T | P | Nov-Dec | PH | E |
26 | Barleria elegans Moore ex C.B.Clarke | Acanthaceae | S | P | Nov-Dec | CHP | E |
27 | Barleria cristata L. | Acanthaceae | S | P | Nov-Dec | CHP | N |
28 | Hibiscus sabdariffa L. | Malvaceae | S | P | Aug-Dec | CHP | E |
29 | Rosa chinensis Jacq. | Rosaceae | S | P | Aug-Dec | CHP | E |
30 | Tagetus erecta L. | Asteraceae | H | P | Nov-Dec | HCP | E |
31 | Solanum lycopersicum L. | Solanaceae | H | P | Sep-Dec | CHP | E |
32 | Boehmeria nivea (l.) Gaudich | Urticaceae | H | P | Nov-Dec | CHP | N |
33 | Solanum tuberosum L. | Solanaceae | H | P | Aug-Dec | GEO | E |
* Here, H : Herb; S : Shrub; T : Tree; A : Annual; P : Perennial; N : Native; E : Exotic, PH: Phanerophytes, THP: Therophytes, CHP: Chamaephytes, HCP: Hemicryptophytes, GEO: Geophytes
Table 3
Details of the observed pollen characters of the studied plant species
Sl. No. | Name of the Species | Pollen unit | Pollen size | Aperture type | Aperture condition | Pollen shape | Exine orientation |
01 | Sphagneticola trilobta (L.) Pruski | Monad | Medium | Colpus | Tricolporate | Prolate spheroidal | Echinate |
02 | Lilium candidum L. | Monad | Large | Sulcus | Sulcate,Monosulcate | Oblate spheroidal | Reticulate |
03 | Impatiens balsamina L. | Monad | Medium | Colpus | Colpate,Tetracolpate | Oblate spheroidal | Reticulate |
04 | Zephyranthes citrina Baker | Monad | Large | Sulcus | Sulcate | Oblate spheroidal | Reticulate |
05 | Benincasa hispida (Thunb.) Cogn. | Monad | Large | Colporus | Colporate,Tricolporate | Spheroidal | Reticulate, heterobrochate |
06 | Ageratum conyzoides L. | Monad | Small | Colporus | Colporate,Tricolporate | Prolate spheroidal | Echinate, perforate |
07 | Mimosa pudica L. | Tetrad | Small | No aperature | Inaperturate | Oblate | Areolate,psilate |
08 | Cucurbita maxima Dushesne | Monad | Very large | Porus | Pantoporate,porate | Spheroidal | Echinate |
09 | Zephyranthes rosea Lindle. | Monad | Large | Sulcus | Sulcate | Oblate | Reticulate |
10 | Bauhinia variegata L. | Monad | Large | Colpus | Colpate,Tricolpate | Prolate | Reticulate |
11 | Tradescantia pallida (Rose) D.R.Hunt | Monad | Medium | Sulcus | Monosulcate | Subprolate | Microreticulate |
12 | Ipomoea cairica (L.) Sweet | Monad | Large | Porus | Porate,Pantoporate | Spheroidal | Echinate |
13 | Ipomoea bahiensis Willd. | Monad | Large | Porus | Porate,Pantoporate | Spheroidal | Echinate |
14 | Malastoma malabathricum L. | Monad | Small | Colporus | Colporate,Tricolporate | Prolate spheroidal | Gemmate,verrucate, scrabrate |
15 | Alternathera sessilis (L.) R.Br. ex DC. | Monad | Small | Porus | Pantoporate | Spheroidal | Reticulate |
16 | Luffa aegyptiaca Mill. | Monad | Large | Colporus | Colporate,Tricolporate | Spheroidal | Reticulate |
17 | Mikania micrantha Kunth | Monad | Small | Colporus | Colporate | Spheroidal | Echinate |
18 | Averrhoa carambola L. | Monad | Small | Colpus | Colpate,Tricolpate | Oblate | Microreticulate |
19 | Ziziphus jujube Mill. | Monad | Small | Colporus | Colporate | Oblate | Rugulate |
20 | Rosa alba L. | Monad | Medium | Colporus | Colporate | Prolate spheroidal | Perforate |
21 | Jasminum multiflorum (Burm.) Andrews | Monad | Medium | Colporus | Colpo rate, Tricolporate | Spheroidal | Reticulate |
22 | Luffa acutangula (L.) Roxb. | Monad | Large | Colporus | Colporate | Spheroidal | Reticulate |
23 | Hibiscus mutabilis L. | Monad | Very large | Porus | Porate, Pantoporate | Spheroidal | Echinate |
24 | Hibiscus syriacus L. | Monad | Very large | Porus | Porate, Pantoporate | Spheroidal | Echinate, Perforate |
25 | Acacia auriculiformis A.Cunn.ex Benth | Polyad | Large | Porus | Porate | Spheroidal | Psilate |
26 | Barleria elegans S.Moore ex C.B.Clarke | Monad | Large | Colpus | Colpate, Tricolporate | Oblate Spheroidal | Reticulate, scrabrate |
27 | Barleria cristata L. | Monad | Large | Colpus | Colpate Tricolporate | Oblate Spheroidal | Lophoreticulate, scrabrate |
28 | Hibiscus sabdariffa L. | Monad | Very large | Porus | Porate,Pantoporate | Spheroidal | Echinate |
29 | Rosa chinensis Jacq | Monad | Medium | Colporus | Colporate, Tricolporate | Prolate spheroidal | Striate, Perforate |
30 | Tagetus erecta L. | Monad | Small | Colporus | Tricolporate | Spheroidal | Echinate |
31 | Solanum lycopersicum L. | Monad | Small | Colporus | Colporate | Oblate spheroidal | Microechinate |
32 | Boehmeria nivea (l.) Gaudich | Monad | Large | Porus | Porate,Pantoporate | Spheroidal | Echinate |
33 | Solanum tuberosum L. | Monad | Medium | Colporus | Colporate,Tricolporate | Spheroidal | Psilate |
*Pollen Size- Small = 10–25 µm, Medium = 25–50 µm, Large = 50–100 µm, very large = 100–200 µm (Erdtman, 1945)
Shape and Size
In the studied plant species, the pollen grains were observed to be spheroidal shaped in Boehmeria nivea, Tagetus erecta, Hibiscus sabdariffa, Hibiscus mutabilis, Hibiscus syriacus, Luffa acutangula, Jasminum multiflorum, Luffa aegyptiaca, Mikania micrantha, Ipomoea cairica, Ipomoea bahiensis, Cucurbita maxima and Benincasa hispida.
The pollen grains of Sphagneticola trilobta, Ageratum conyzoides, Malastoma malabathricum, Rosa alba, and Rosa chinensis were found to be prolate spheroidal shaped; and prolate shaped in Bauhinia variegata. The pollen grains were oblate spheroidal in Lilium candidum, Impatiens balsamina, Zephyranthes citrina, Barleria elegans, Barleria cristata, and Solanum lycopersicum. The pollen grains were found oblate shaped in Averrhoa carambola, Ziziphus jujube, Zephyranthes rosea and Mimosa pudica.
The pollen grains in all the studied species were found as monad except in Mimosa pudica, where the pollen grains were found as tetrad and in Acacia auriculiformis, where the pollen grains were found as polyad.
Aperture
Inaperturate pollen grains were found in Mimosa pudica of Fabaceae family. In the studied dicot species, pollen grains of Sphagneticola trilobta, Benincasa hispida, Ageratum conyzoides, Malastoma malabathricum, Luffa aegyptiaca, Jasminum multiflorum, Barleria elegans, Barleria cristata, Rosa chinensis and Tagetus erecta were found to be tricolporate and in Bauhinia variegata and Averrhoa carambola, the pollen grains were found to be tricolpate.
In Solanum lycopersicum, Luffa acutangula, Ziziphus jujube, Rosa alba and Mikania micrantha, colporate type of pollen grains were found.
Tetracolpate type of pollen grains were found in Impatiens balsamina and porate type of pollen grains in Acacia auriculiformis. Monosulcate pollen grains were found in Lilium candidum, and Tradescantia pallida whereas, sulcate pollen grains were found in Zephyranthes citrina and Zephyranthes rosea. In Cucurbita maxima, Ipomoea cairica, Ipomoea bahiensis, Alternathera sessilis, Hibiscus mutabilis, Hibiscus syriacus, Hibiscus sabdariffa and Boehmeria nivea, pantoporate type of pollen grains were observed.
Exine Ornamentation
The ornamentation on the exine surface varies greatly in both monocot and dicot groups. In monocot species, the exine surface was found to be reticulate in Lilium candidum, Zephyranthes rosea and Zephyranthes citrina.
In the dicot group, the exine surface was echinate in Sphagneticola trilobta, Ageratum conyzoides, Cucurbita maxima, Ipomoea bahiensis, Ipomoea cairica, Mikania micrantha, Hibiscus mutabilis, Hibiscus syriacus, Hibiscus sabdariffa, Tagetus erecta and Boehmeria nivea. In both Tradescantia pallida and Averrhoa carambola, the exine surface was found to be microreticulate. In Acacia auriculiformis, the exine surface was psilate type. The exine surface was found to be striate and perforate in Rosa chinensis; perforate in Rosa alba; areolate,psilate in Mimosa pudica ; rugulate in Ziziphus jujube ; reticulate, heterobrochate in Benincasa hispida; echinate, perforate in Ageratum conyzoides; reticulate and scrabrate in Barleria elegans; lophoreticulate, scrabrate in Barleria cristata and microechinate in Solanum lycopersicum. In Malastoma malabathricum, the exine surface was found to be gemmate, verrucate and scrabrate.