Mithilesh Chaturvedi

Pollen morphology of Oryza (Poaceae)

Pollen morphological studies of 19 species of Oryza (Poaceae) were carried out using LM and SEM. Eleven exine surface patterns are distinguished at x 20,000 magnification under SEM. These are categorised into three basic types: granulose, spinulose and insular. O. brachyantha‐ a genomically unrelated species, and two species (O. granulata and O. meyeriana) comprising the O. meyeriana complex have spinulose exine surfaces. The O. ridleyi complex which also contains two species (O. longiglumis and O. ridleyi) is characterised by a granulose exine pattern. In the O. officinalis complex and the O. sativa complex, both granulose and insular exine patterns have been observed in different species. The largest pollen grains occur in the O. sativa complex, which contains both cultivated species and their wild relatives.

Pollen morphology of Sorghum Moench – Sections Eu-sorghum and Para-sorghum

Abstract Pollen morphological studies have been carried out by SEM on 23 species of Sorghum (Gramineae) in order to resolve the exine surface patterns in sections Eu-sorghum (subsection Arundinacea-series Spontanea and Sativa and subsection Halepensia), and Para-sorghum. Basically, two exine ornamentation types have been observed viz. granular and insular. In section Eu-sorghum, series Spontanea and Sativa (of subsection Arundinacea) are heterogeneous having both types of exine pattern. In the same section, subsection Halepensia is characterised by having only a granular exine. Section Para-sorghum shows a marked pollen morphological similarity with subsection Halepensia of section Eu-sorghum. Snowdens concept that the two series Spontanea and Sativa are closely related and that the cultivated Sorghum (series Sativa) might have evolved from the wild Sorghum (series Spontanea), is supported by the present observations.

Pollen morphology of Basmati cultivars (Oryza sativa race Indica) – exine surface ultrastructure

Pollen morphological studies using LM and SEM have been carried out on six cultivars of Basmati – a variety of cultivated species Oryza sativa race Indica. SEM study at a magnification of ×20,000 revealed distinct variations in pollen exine surface patterns, in relation to the arrangements of fine surface excrescences (spinules or granules) and their clustering patterns forming small areas or insulae. Three distinctly different insular patterns occur in cultivars Basmati-370, Karnal local and Type-9. Cultivar Bakul Joha is characterized by free spinules. Mixed type i.e. both free and fused excrescences were observed in cultivars Bengali Joha and Bhog Maniki but they can be differentiated on the basis of the dimensions of the excrescences.

Cytopalynological studies of arachis (leguminosae)

Abstract The present cytopalynological study relates to the pollen morphology of Arachis L., comprising diploid wild species, tetraploid species including the cultivated A. hypogaea (ground nut), diploid interspecific hybrids, and triploids and hexaploids of cultivars of A. hypogaea and of diploid wild species. In general, the pollen grains are 3-zonocolpate and reticulate/fossulate and trends in pollen variations have been noticed with regard to aperture and exine ornamentation. The size, shape and number of lumina (per unit area) as seen in SEM picture have provided the basic parameter for taxonomic differentiation of the species and even cultivars (in the case of A. hypogaea), and in the assessment of inheritance pattern in the hybrids.

An Analysis of Honey Bee Pollen Loads from Banthra, Lucknow, India

Abstract The botanical composition of bee pollen loads, collected between January and April, 1970, is presented, and discussed in relation to seasonal preferences.

Cytopalynology of Celosia L.

Abstract Cytopalynological studies have been carried out in Celosia (Amaranthaceae) — a polyploid species complex having both wild and cultivated species. The studies include C. trigyna 2× (wild), C. argentea 4× and 8× (wild), 8× colchiploid, 12× (synthetic), C. cristata 4× (cultivated: varieties and cultivars), C. whiteii 12× (wild), and F1 hybrids (i) C. argentea 4× (wild) × C. argentea 8× (wild)-6×, (ii) C. argentea 12× (synthetic) × C. whiteii 12× (wild)-12×, (iii) C. whiteii 12× (wild) × C. argentea 12× (synthetic)-12×. Though the genus is stenopalynous with pantoporate pollen grains, cytotypic differences have been observed in pollen size, exine ornamentation and exine thickness even at varietal and cultivar levels. C. trigyna, the diploid wild species is clearly separated by pollen size and exine ornamentation from 4×, 8× and 12× species. In the F1 hybrids, the exine characters are intermediate between the parents. In reciprocal 12× F1 hybrids, the pollen size is variable and resembles that of the ...

Pollen exine ornamentation in the F2 generation of an interspecific hybrid of Chorisia (Bombacoideae, Malvaceae) in relation to inheritance pattern

Pollen morphology in ten plants of F2 progeny of an interspecific tree hybrid, Chorisia insignis H. B.& K.×C. speciosa St. Hil (Bombacoideae, Malvaceae) has been studied with a view to have an insight in to the effect of hybridization on the pollen morphological features in F2 generation. The study is a sequel to an earlier study on the pollen morphology of Chorisia species and their F1 hybrid, in which case the hybrid pollen uniformly exhibited the apertural features of the male parent and exine features of the female parent. In the F2 progeny the pollen grains display the apertural feature of the male parent in all the plants. However, with regard to exine ornamentation, variability has been observed. Of the ten plants, two plants exhibit the exine features of the male parent showing empty lumina (without bacula), five plants have their pollen exactly like that of the F1 plant (showing prominent columellar heads in the lumina of the apocolpium region) and the remaining three plants showing columellae in lumina of both apocolpium and mesocolpium region being different from the above types. It has been inferred that the variability in the exine pattern in F2 pollen indicates that the pollen exine pattern in hybrids, perhaps, is not unequivocally controlled by sporophytic or gametophytic genomes.

Pollen analysis of some spring honeys from the western Himalayan region of Uttar Pradesh, India

In the apiaries of the western Himalayan region (Kumaon and Garhwal hills) of Uttar Pradesh, the honey is harvested twice in a year i.e. in autumn and spring. Out of 12 spring samples of honey analysed, there are 10 unifloral and 2 multifloral samples. The dominant entomophilous pollen types in unifloral samples areBrassica, and Rosaceae-Prunus type. It has been suggested that the anemophilous pollen types namely,Alnus andRumex may be used as markers of honey samples originated from the Himalayan region. The data presented in the paper are useful in standardization of honey samples.

Pollen Grains of Saccharum Robustum Brandes and Jesw. Ex Grassl

Abstract Normally, pollen grains of Saccharum robustum are 1-porate, annulate and operculate. Double grains occur which may be dumb-bell shaped with one pore at either side of the dumb-bell. Single, 2-porate grains are however met with and there are also double grains with only 1 pore. The significance of these different morphological types is discussed.

Studies on the pollen morphology of someCapparis L. (Capparaceae) species

Pollen morphology of seven species ofCapparis L., has been studied using light microscope and scanning electron microscope. Ultra surface patterns coupled with endocolpium characters of pollen grains are useful for distinguishing the species.