Doubling of chromosomes of pearl millet napier hybrids and preliminary screening based on stomatal characteristics

Abstract

The objective of the present work was to induce chromosome doubling in sterile triploid pearl millet napier hybrids to develop fertile hexaploids. Colchicine, an alkaloid from Colchicum autumnale, was used for polyploidization. F1 seeds of the cross combination ICMV 05666 × FD 471 and setts of PMN hybrid CO (BN) 5 were used for treatment. F1 seeds were treated with 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 and 1.0% of colchicine for different durations of 6hrs, 8hrs, 12hrs and 24hrs and setts treated with 0.05, 0.06, 0.07, 0.08, 0.09 0.10, 0.15, 0.20, 0.25 and 0.30% of colchicine at 3hrs intervals for 2 days. The treated seeds and setts were evaluated for germination (%), survivability (%) and stomatal measurements. In seed treatment, highest germination (78.0) and survival per cent (62.0) was recorded at 0.04% for 6hrs treatment, respectively. Pertaining to sett treatment, highest germination and survival per cent was recorded at 0.05%, followed by 0.06%, the least being at 0.25 and 0.30%. With regard to stomatal length, highest mean value (61.03 ± 7.44) was recorded from seedlings raised with seed treated at 0.06% for 24hrs with a range of 53.59 - 68.46 μm and in sett treatment raised seedlings, it was highest (56.72 ± 4.00 μm) at 0.20% with a range of 50.34 - 68.41 μm, against the control with 46.27 ± 0.57 μm. Among various treatments, seed treatment at 0.06% for 24hrs and 0.07% for 12hrs and sett treatment at 0.15 and 0. 20% were identified to be efficient in generating variants. However, these variants have to be further studied for ploidy confirmation via. Flow cytometry and chromosomal counts.

Keywords

• Pearl millet napier hybrids
• colchicine
• seed treatment
• sett treatment and stomatal size