جستجوی مقالات مرتبط با کلیدواژه « hypericum » در نشریات گروه « زیست شناسی »

In this research, pollen grains of ten species and two subspecies of the genus Hypericum in Iran belonging to four sections were studied using light and scanning electron microscopy. The pollen grains are monad, isopolar to subisopolar and heteropolar, prolate, subprolate, spheroidal and prolate- spheroidal in shape, small to medium in size. The outline of pollen grains varies from round to triangular, quadrangular and ovate from polar view and elliptical, tetrahedral, quadrangular, round and ovate from equatorial view; 3 and 4 syncolporate to 3, 4 and 6 zonocolporate. Based on exine sculpturing, pore shape, size and muri thickness, the examined species are divided in two main types including scrobiculate and micro reticulate and 2 subtypes including small pore / thick muri and large pore / thin muri. The pores are arranged from irregular to regular-irregular with regular intervals. The current result revealed taxonomically important palynological data of the genus Hypericum. These traits can be used for infrageneric classification, especially at sectional and species levels.

Original meiotic chromosome counts are presented for 17 species in nine families of angiosperms from Iran. Chromosome counts for six species including: Tanacetum polycephalum subsp. duderanum (Asteraceae) (n=18), Cardaria draba subsp. chalepensis (Brassicaceae) (n=32), Minuartia lineate (Caryophyllaceae) (n=10), Silene latifolia subsp. persica (Caryophyllaceae) (n=12+1B), Epilobium confusum (Onagraceae) (n=10), and Rumex scutatus (Polygonaceae) (n=15) are new reports. Also, the diploid level of n=9 for Nepeta racemosa is reported here for the first time.