Development Of Triploid Cultivars Research Articles

Main results of apple breeding at the Russian Research Institute of Fruit Crop Breeding

The intensive target work for apple assortment improvement is being carried out at the Russian Research Institute of Fruit Crop Breeding (VNIISPK). A large interdisciplinary team of researchers takes part in creating cultivars. Promising areas of apple breeding for our institution are: 1. The development of triploid apple cultivars having more regular fruiting, high marketability of fruits and higher autogamy. 2. The development of cultivars immune and highly resistant to scab. 3. The development of triploid cultivars with immunity to scab. 4. Т he development of columnar cultivars for intensive and super intensive orchards. 5. Т he development of apple cultivars with improved biochemical composition of fruits. For the entire period of selection work, artificial pollination in the amount of 5.2 million flowers was carried out, 912 thousand annual apple seedlings were grown, 249 elite seedlings were produced and 54 apple cultivars were created and included in the State Register of breeding achievements admitted for use (zoned). Brief economical and biological descriptions of them are given in this paper. The best diploid apple cultivars Veteran, Orlik, Orlovskoye Polosatoye and Pamyt Voinu as well as triploid cultivars Avgusta, Ministr Kisilev, Orlovsky Partizan, Osipovskoye and Sinap Orlovsky adapted to local conditions are already widely known and introduced into production. Triploid cultivars having immunity to scab Vavilovskoye, Maslovskoye, Rozhdestvenskoye and Yablochny Spas as well as columnar cultivars Vostorg, Girlyanda, Orlovskaya Yesenia, Poezia and Priokskoye are of special interest. The cultivars with improved biochemical composition of fruits are of great interest. The widespread introduction of new promising apple cultivars of the Institute's breeding into industrial plantings will undoubtedly contribute to import substitution of fruit products in Russia.

Development of triploid hybrids in asparagus breeding employing a tetraploid landrace

The development of triploid cultivars from crosses between the tetraploid landrace ‘Morado de Huetor’ and diploid commercial cultivars was studied in this work. Fertility of both 4x × 2x and 2x × 4x crosses, as measured by fruit set and number of seeds per fruit, and germination rate of triploid seeds, were studied in order to assess the viability of producing commercial seeds. Seven triploid hybrid progenies were included in a progeny test together with thirteen experimental tetraploid hybrids and four cultivars (‘Grande’, ‘UC157-F2’, ‘Purple Passion’ and ‘Morado de Huetor’). Marketable spear production and mean diameter of spears were evaluated in both 2007 and 2008. Crosses 4x × 2x were more successful than 2x × 4x, and a wide variation from high to very low fertility within tetraploid females was found. Germination rate of triploid seeds was similar to diploid ones. After 2 years of evaluation experimental hybrid triploids were more productive than tetraploids with values similar to the highest yielding diploid cultivar (‘Grande’). Spear diameter of triploid hybrids was in general thicker than the tetraploid hybrids and significantly thinner than the standard cultivars ‘Grande’ and ‘Purple Passion’ (tertraploid). These results suggest that the development of new triploid cultivars (4x × 2x) employing a tetraploid landrace from a different genetic background of current diplods could be interesting in asparagus breeding, broadening the spectrum of cultivated asparagus cultivars.

‘Helene’ Rose of Sharon (Althea)1

Abstract Hibiscus syriacus L., commonly known as rose of sharon or althea, is a plant which can endure extreme heat, drought, and poor soil to provide a freeflowering summer shrub. The landscape qualities of the species have been enhanced by the development of triploid cultivars with compact growth habit; leathery, dark green leaves; sterility; and abundant, continuous flowering throughout the summer. In 10 years ‘Diana’ (1), the first introduced triploid cultivar, has become highly esteemed and is now the leading cultivar grown by nurserymen.