Cytomorphology of induced octoploid Chili pepper (Capsicum annuum L.)

Abstract

Octoploidy was induced in Chili pepper (Capsicum annuum cultivar 'cerasiformis') through the application of colchicine and the cytomorphological features of two octoploid plants were described. In general, the octoploids did not exhibit gigas characters when compared to the tetraploids; on the contrary they were less vigorous, suggesting that the optimum and desirable ploidy level for Capsicum is probably tetraploid. Chromosome associations such as octovalents and hexavalents, in addition to IVs, IIIs, IIs and Is, were recorded at diakinesis and metaphase I. Meiosis was highly irregular and the pollen and seed fertility was very low. Cytological features of octoploid Chili peppers are compared with octoploids of Physalis and Petunia.

Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae)

“…In addition, although polyploidy is very rare in Capsicum , Greenleaf (1947) , Pickersgill (1977) and Jha et al (2012) described what they believed to be natural polyploids, triploids and tetraploids with 2n = 3x = 36 and 2n = 4x = 48, respectively. Polyploid forms can also be induced as has been shown ( Gyorffy 1939 ; Nishiyama 1939 , 1940 ; Pal and Ramanujam 1939 ; Pal et al 1941 ; Aleksic 1960 ; Palfi et al 1961 ; Ohta 1962c ; Siskovic 1962 ; Raghuvanshi and Joshi 1964 ; Indira and Susan 1977 ; Panda et al 1984 ; Rao 1987 ; Ishikawa et al 1997 ; Ishikawa 2001 ; Kumar and Raja Rao 2003 ; Kumar et al 2004 ; Takizawa et al 2008 ; Kulkarni and Borse 2010 ).…”

Induced polyploidy with gigas expression for root traits inCapsicum annuum(L.)

“…Earlier reports used colchicine treatment (0.05–0.4%) on seeds to create polyploids (Pal and Ramanujan 1939, Panda et al. 1984) but we also used the seedling shoot tip method which was not tested earlier.…”

Synthetic polyploidy in spice crops: A review

“…Few of the treated plants exhibited various abnormalities in growth, such as slow growth, thickening of leaves, and doubling of flowers, and they were identified as tetraploid and triploid using chromosome counting. There were other reports on the colchicine treatment of chili seeds to induce polyploidy (Pal et al, 1941;Panda et al, 1984; Crop Science Raghuvanshi & Joshi, 1964). It is unusual to see octoploids produced directly from diploids.…”

“…Panda et al. (1984) reported octaploid chilies from the colchicine treatment, where the size and vigor of the plants significantly decreased compared to tetraploids, indicating that an increase in the ploidy level is not necessarily accompanied by gigas effects. Similarly, Kulkarni and Brose (2010) demonstrated the potential use of colchiploidy to generate novel alterations in root systems.…”