Callus induction and plant regeneration of tomato (Lycopersicon esculentum cv. IPA 5) via anther culture

Abstract

SUMMARY Different growth regulators combinations were tested on the production of anther callus in tomato cultivar

Meiotic metaphase I to telophase II as the most responsive stage during microspore development for callus induction in tomato (Solanum lycopersicum) anther cultures

“…In our cul tures, most of the calli were mixoploid, and not a sin gle one was ex clu sively hap loid. How ever, mixoploidy was re ported as frequent in calli and regenerant plants of other to mato cultivars (Levenko et al 1977, Zamir et al 1980, Brasileiro et al 1999, Zagorska et al 2004, and our flow cytometrical anal y sis dem on strated the pres ence of hap loid cells within the mixoploid callus, sup port ing the no tion that mixoploidy seems to be due to the spon ta ne ous dou bling of the chro mosome num ber in some ini tially hap loid cells. Doubling is be lieved to be orig i nated by nu clear fu sion or endoreduplication, as a re sult of the use of growth fac tors in the in duc tive me dium and the insta bil ity of hap loid genomes (Sunderland et al 1974, Levenko et al 1977, Zamir et al 1980, Ziv et al 1984, Brasileiro et al 1999.…”

“…We showed that some cal lus cells pos ses two nu clei (Fig. 3C), which is the first step for ge nome dou bling by nuclear fu sion (Sunderland et al 1974, Levenko et al 1977, Zamir et al 1980, Ziv et al 1984, Brasileiro et al 1999. In fact, this mech a nism was proved to be re spon si ble for the spon ta ne ous ge nome du plica tion also dur ing Datura, bar ley and maize haploid embryogenesis (Sunderland et al 1974, Kasha et al 2001, Testillano et al 2004, González-Melendi et al 2005.…”

“…Some au thors sug gested that young, uni-cel lu lar micro spores are the most respon sive for both S. lycopersicum (Levenko et al 1977, Gulshan andSharma 1981) and hy brids between S. lycopersicum and S. peruvianum (Cappado cia and Ramulu 1980). On the other hand, mei osis has also been pos tu lated as the key stage for obtain ing cal lus (Gresshoff and Doy 1974, Zamir et al 1980, Sum mers et al 1992, Brasileiro et al 1999. Shtereva et al (1998) re stricted this phase to meiocytes from prophase I to metaphase II.…”

“…This win dow was ini tially proposed by some au thors to en com pass the stages of the young uni-cel lu lar microspore (Levenko et al 1977, Gulshan andSharma 1981), whereas other stud ies pointed to the meiocyte Doy 1972, Zamir et al 1980). In the last de cade, sev eral re ports sug gested that the crit i cal pe riod co in cides with mei otic de vel op ment and the tetrad stage (Sum mers et al 1992, Brasileiro et al 1999 In this work, we ad dressed the cel lu lar char ac terisa tion of the in vivo to mato microspore/pol len devel op ment, iden ti fy ing the most re spon sive stage/s dur ing flower de vel op ment to in duce androgenesis. We set up an an ther cul ture pro to col to in duce calli and re gen er ate com plete to mato plants, and re lated the microspore de vel op men tal stage of the do nor an thers with their per cent age of cal lus pro duc tion.…”

Induced androgenesis in tomato ( Lycopersicon esculentum Mill.). III. Characterization of the regenerants

“…The rapid polyploidization of cells cultured in vitro as well as the great number of mixoploid, diploid and polyploid regenerants obtained by anther and tissue cultures seem to be due to variations in both the quality and quantity of the components of the nutrient medium, such as 2,4-D, casein hydrolysate, BAP, kinetin, etc. (Engvild 1974;Zagorska et al 1974;Hu 1986;Karp 1991;Brasileiro et al 1999), as well as to the instability of the haploid cells, the latter being observed in tomato (Koornneef et al 1989). …”