Anther culture and long-term culture ability of androgenic calli in durum wheat (Trticum durum Desf.)

Sharad Tiwari

Plant Tissue Culture Laboratory, Department of Plant Breeding and Genetics, Jawaharlal Nehru Agricultural University, Jabalpur 482004, India

Summary

To study the effects of culture media and genotypes on anther culture, anthers of sixteen durum wheat genotypes were cultured on N₆ NB medium with BA and NAA and N₆ DK medium with 2,4-D and kinetin. Overall, the calli and plants obtained were more than 1.7 times higher with N₆ DK medium as compared to N₆ NB. Among sixteen genotypes tested, nine genotypes responded for androgenesis in vitro. Genotype HI 8381 produced maximum plants (nearly 4 per 100 anthers) followed by A 9-30-1, which produced 2.25 plants on N₆ DK medium. Formation of androgenic calli and regeneration of green plants were significantly higher with maltose and agarose as compared to media with sucrose and agar combination. For long-term maintenance androgenic calli were sub-cultured on three different combinations of MS media. Medium with 2,4-D and silver nitrate maintained embryogenic status of androgenic calli more affectively than other two media with 2,4-D alone.

Key words: Triticum durum, anther culture, genotypes, culture media, long-term culture.

Introduction

In vitro techniques and methods for genetic manipulation of higher plants have made considerable progress in recent years. The contribution of this area of research is increasing with a major role of haploids in crop improvement. The haploidization and subsequent chromosome doubling is particularly useful as an alternative to the numerous cycles of inbreeding or back crossing needs to obtain pure lines in conventional breeding program.

The production of doubled haploid lines of cereals from anther culture is limited by relatively low callus/ embryoid induction frequency, genotype dependent response and poor regeneration, a large number of which are albino plants. In durum wheat, Headwiger and Heberle-Bors (1986) reported very low frequency of haploid plants from anther culture. Foroughi-Wehr and Zeller (1990) observed embryogenesis in calli produced from durum wheat anther culture but only of non-regenerative type. Following the reports of considerable regeneration of androgenic plants by Ghaemi et al. (1995) and Tiwari (1997), durum wheat should no more be assigned recalcitrant status.

The use of anther culture as a tool in genetic improvement of most of the cereals has been hampered by the fact that plant regeneration from various cultures is of low frequency and of short duration. Maintenance of embryogenic source for prolonged duration is essential for conducting biochemical and physiological studies, mutation and in vitro selection for genetically Modifying the material. However, so far in cereals we do not have any reports of efficient methods for long-term maintenance of androgenic cultures except in barley, where embryogenic cultures of androgenic source have been studied (Tiwari et al. 1990 a, b). Present study was conducted to determine the influence of several genotypes and medium components on the androgenic plant regeneration from durum wheat anther culture. Another objective of this study was to investigate the possibility of long-term culturing of androgenic calli of durum wheat.