Semicompact canopy form in mixoploid plants differentiated from the endosperm of Pyrus communis cv. Natanzi: Evidence from flow cytometric analysis and anatomical and morphological traits

Abstract Endosperm culture can be considered a method to achieve polyploid plants. An experiment was conducted to determine the ploidy levels in leaf cells of plantlets originating from the endosperm and cotyledonary segment explants after organogenesis. The ploidy level of plantlets was determined by flow cytometry. Also, anatomical and morphological traits of the analysed plantlets were compared to identify the phenotypic difference in the plants. Flow cytometric analysis revealed that plantlets with cotyledon origin were diploid, while plantlets differentiated from the endosperm were mixoploid. Mixoploid and diploid plants differed in genome size. Mixoploidʼs leaves developed with a steep angle (27.23 ± 2.62°, n = 3), low leaf area index (0.233 ± 0.002, n = 3) and small cross‐sectional area of the plant canopy (104.2 ± 2.11 cm2, n = 3) at the maturity of the leaf. The higher light interception (39.137 ± 0.047 μmol m−2 s−1, n = 3) was also recorded in mixoploid plants compared to diploid plants. The shorter internode in the upper part of, and longer internode in the lower part of, the plant canopy is consistent with the semicompact phenotype of mixoploid plants. Their stomatal conductance values were higher than those in diploid plants. The light interception showed a strong positive correlation with stomatal conductance. The comparison of stomatal density and length in haploid, diploid and triploid leaves of mixoploid plants has revealed that with the increase in ploidy level, stomatal density decreased because of enlargement in stomatal length. This study offers trees with a semidense canopy and better photosynthesis conditions for semidense orchard construction.