Exploitation of morphological features of bud and anther development for prediction of stages of microsporogenesis and microgametogenesis in pepper

摘要

Doubled haploid (DH) plant production assumes significant importance for breeders not only for mapping of genes of agronomic importance but also to shorten the breeding cycle for production of new hybrids and homogenous varieties. Microspore culture is the fastest method for production of doubled haploid plants. The success of haploid production in any species is dependent on the stage at which microspores or pollens are cultured, as this stage is crucial for switch from gametophytic to embryogenic mode of development of pollen in vitro. In the present investigation, we attempted to identify visible morphological markers in the flower bud and anthers in pepper (Capsicum annuum L.) for predicting the stages of growth of the microspores contained within them. Uninucleate microspore stage has been found to be most conducive stage for induction of androgenesis in pepper. In our study, the morphological markers for this stage were found to be: (i) size of flower bud in the range of 6-7 mm; (ii) length of anther approximately 450 mu m; (iii) corolla slightly longer than that of the calyx; and (iv) green anthers with purple pigmentation at the apical end.