**8. Conclusion and recommendations**

Each of the androgenesis methods including anther, shed-microspore and isolated microspore culture has advantages or disadvantages from each other. Among the eggplant androgenesis studies in the world, there are applicable protocols for anther culture, the most commonly used method, while the use of shed-microspore culture is not widespread and has not been given enough attention. As for the isolated microspore culture, the studies on indirect microspore embryogenesis have been tried to develop for a long time, and successful protocols have been improved in recent years. However, a practical direct embryogenesis protocol in isolated microspore culture is still missing.

When the recent eggplant androgenesis studies were evaluated, in the latest anther culture study, Vural informed the highest embryo yield to be 320 embryos/100 anthers [46]. Another striking improvement was performed by a Spanish research group who recently made major advances in eggplant microspore culture, that the microspore embryogenesis response is generally caused by genotype rather than by the culture protocol. This group has developed a superior DH eggplant line with very high androgenic response from a DH population improved from a hybrid cultivar with high androgenic response and their inbred lines. The haploidy performance of this superior line has folded the performance of its hybrid parent 1.6 times in anther culture and 4.1 times in microspore culture. These important improvements have shown the significance of population development and the use of DH lines to obtain haploid plant in eggplant, which is still considered to be recalcitrant between tomato and tobacco in Solanaceae [82].

It has long been known that hybrids and DH lines exhibit higher haploid performance than their parents. Therefore, at the beginning of the recommendations to increase the efficacy of microspore embryogenesis in eggplant, the development of populations, carrying the genes responsible from high androgenic performance,

**85**

*Development of Androgenesis Studies on Eggplant (*Solanum melongena *L.) in Turkey…*

comes first by means of the crosses between the high androgenic hybrids, genotypes and in particular DH lines and non-androgenic elite genotypes. Other suggestions are to focus more on the isolated microspore culture technique which has a much higher embryo or callus yield potential than the anther culture and to improve more practical protocols in particular for direct embryogenesis. Therefore, it may be dwelt on the development of shed-microspore culture protocols since it has an application between anther culture and isolated microspore culture. However, shed-microspore culture is more practical than isolated microspore culture and has the potential for higher embryo yield than anther culture. In addition, the culture media and also the culture conditions can be optimized to increase embryo yield, embryo quality and plant regeneration rate in eggplant androgenesis by different chemical, biochemical, PGR or especially phytohormones that were tested and

Finally, it is considered beneficial to increase in vitro androgenesis studies also in

AT3 medium consisted of 13 mM KNO3, 8.6 mM (NH4)2 SO4, 2.9 mM KH2 PO4,

B medium Kyo and Harada (1986) nutrient medium (consisted of KCl,

; MgSO4.7H2O, 0.25 g L<sup>−</sup><sup>1</sup>

microelements according to Murashige and Skoog [72]

1.1 mM CaCl2 .2H2O, 0.7 mM MgSO4 .7H2O, 10 mM MES buffer, 8.6 mM glutamine, 0.25 M maltose and Fe-EDTA, vitamins and

; CaCl2, 0.11 g L<sup>−</sup><sup>1</sup>

and 1 mM phosphate buffer of pH 7) [83]

and Mannitol

*DOI: http://dx.doi.org/10.5772/intechopen.88299*

proved in other plant species.

**Icons and abbreviations**

% percent

L liter UV ultraviolet

**Abbreviations**

°C degrees Celsius Co60 cobalt 60 CO2 carbon dioxide g L<sup>−</sup><sup>1</sup> gram/liter M molar

mg L<sup>−</sup><sup>1</sup> milligrams/liter

ABA abscisic acid

AgNO3 silver nitrate

BA N6-benzyladenine BAP 6-benzylaminopurine

DH doubled haploid IAA indole-3-acetic acid IBA indole-3-butyric acid LED light-emitting diode NAA α-naphthalene acetic acid

AVG aminoethoxy-vinylglycine

1.49 g L<sup>−</sup><sup>1</sup>

(0.3 M) 54.63 g L<sup>−</sup><sup>1</sup>

MS Murashige and Skoog [72] nutrient medium

DAPI 4′-6-diamidino-2-phenylindole DDV-C Dumas de Vaulx—C medium [17] DDV-R Dumas de Vaulx—R medium [17]

**Icons**

wild *Solanum* species to develop rootstock.

*Development of Androgenesis Studies on Eggplant (*Solanum melongena *L.) in Turkey… DOI: http://dx.doi.org/10.5772/intechopen.88299*

comes first by means of the crosses between the high androgenic hybrids, genotypes and in particular DH lines and non-androgenic elite genotypes. Other suggestions are to focus more on the isolated microspore culture technique which has a much higher embryo or callus yield potential than the anther culture and to improve more practical protocols in particular for direct embryogenesis. Therefore, it may be dwelt on the development of shed-microspore culture protocols since it has an application between anther culture and isolated microspore culture. However, shed-microspore culture is more practical than isolated microspore culture and has the potential for higher embryo yield than anther culture. In addition, the culture media and also the culture conditions can be optimized to increase embryo yield, embryo quality and plant regeneration rate in eggplant androgenesis by different chemical, biochemical, PGR or especially phytohormones that were tested and proved in other plant species.

Finally, it is considered beneficial to increase in vitro androgenesis studies also in wild *Solanum* species to develop rootstock.

#### **Icons and abbreviations**

#### **Icons**

*Sustainable Crop Production*

**8. Conclusion and recommendations**

*Colchicine treatment with lanolin. Fruits on the DH branches.*

**Figure 9.**

microspore culture is still missing.

Each of the androgenesis methods including anther, shed-microspore and isolated microspore culture has advantages or disadvantages from each other. Among the eggplant androgenesis studies in the world, there are applicable protocols for anther culture, the most commonly used method, while the use of shed-microspore culture is not widespread and has not been given enough attention. As for the isolated microspore culture, the studies on indirect microspore embryogenesis have been tried to develop for a long time, and successful protocols have been improved in recent years. However, a practical direct embryogenesis protocol in isolated

When the recent eggplant androgenesis studies were evaluated, in the latest anther culture study, Vural informed the highest embryo yield to be 320 embryos/100 anthers [46]. Another striking improvement was performed by a Spanish research group who recently made major advances in eggplant microspore culture, that the microspore embryogenesis response is generally caused by genotype rather than by the culture protocol. This group has developed a superior DH eggplant line with very high androgenic response from a DH population improved from a hybrid cultivar with high androgenic response and their inbred lines. The haploidy performance of this superior line has folded the performance of its hybrid parent 1.6 times in anther culture and 4.1 times in microspore culture. These important improvements have shown the significance of population development and the use of DH lines to obtain haploid plant in eggplant, which is still considered to be

It has long been known that hybrids and DH lines exhibit higher haploid performance than their parents. Therefore, at the beginning of the recommendations to increase the efficacy of microspore embryogenesis in eggplant, the development of populations, carrying the genes responsible from high androgenic performance,

recalcitrant between tomato and tobacco in Solanaceae [82].

**84**


#### **Abbreviations**


#### *Sustainable Crop Production*

