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Morphological and cytological characters for defining Stevia ‘Honeyleaf’ tetraploids
2015
Цвігун, Г. В
Purpose. Determination of peculiarities of anatomical and morphological characters of stevia plants to accelerate the identification of tetraploid forms. Methods. Field, laboratory and analysis-of-variance methods. Results. It was established that larger leaf area index (19–38%), fewer stomata per unit area (by 39–48%), larger diameter of pollen grains (by 42–92%) is a characteristic feature of anatomical and morphological characters of stevia tetraploid forms as compared to diploid ones. Conclusions. The parameters of leaf plate, the size of stomata and diameter of pollen grains are auxiliary selection criteria (rapid test). For tetraploid forms of stevia, leaf area index (the ratio of leaf blade length to width), size of stomata and diameter of pollen grains is truly larger as compared to diploid forms. Chromosomes number determination based on cytological analysis is the major and the most accurate criterion for selection of tetraploid forms, that seems advisable to use it at later stages of selection.
Afficher plus [+] Moins [-]Summarizing 60 years of apple breeding effort (Malus domestica Borkh)
2013
Седов, Є. М | Серова, З. М
The paper highlights results of 60 years of apple breeding activity at the All-Russian Research Institute for Fruit Crop Breeding of RAAS (former Orel Zonal Fruit-Berry Experimental Station). Major selection effort has been applied to apple breeding for higher contents of ascorbic acid and P-active substances in fruit. A pattern of the inheritance of biologically active substances in apple fruits is shown. First time in Russia a large-scale selection has taken place for the purpose of developing domestic scab immune apple varieties (Vf). 20 scab immune varieties have been created and included into the State Register. First time in Russia and in the world a range of triploid apple varieties have been developed through directed diverse chromosome crossings 2x x 4x and 4x x 2x.
Afficher plus [+] Moins [-]Morphological and cytological characters for defining Stevia ‘Honeyleaf’ tetraploids
2015
Г. В. Цвігун
Purpose. Determination of peculiarities of anatomical and morphological characters of stevia plants to accelerate the identification of tetraploid forms. Methods. Field, laboratory and analysis-of-variance methods. Results. It was established that larger leaf area index (19–38%), fewer stomata per unit area (by 39–48%), larger diameter of pollen grains (by 42–92%) is a characteristic feature of anatomical and morphological characters of stevia tetraploid forms as compared to diploid ones. Conclusions. The parameters of leaf plate, the size of stomata and diameter of pollen grains are auxiliary selection criteria (rapid test). For tetraploid forms of stevia, leaf area index (the ratio of leaf blade length to width), size of stomata and diameter of pollen grains is truly larger as compared to diploid forms. Chromosomes number determination based on cytological analysis is the major and the most accurate criterion for selection of tetraploid forms, that seems advisable to use it at later stages of selection.
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