The effects of Rf5 and Rf6 on fertility restoration in Honglian-type cytoplasmic male sterile (CMS) lines of japonica rice (Oryza sativa L. ssp. japonica)

The Honglian (HL)-type cytoplasmic male sterility (CMS) has only been used in the development of three-line indica rice hybrids, and the fertility of HL-type indica CMS lines can be restored by two nonallelic fertility-restorer (Rf) genes, Rf5 and Rf6. For the development of HL-type japonica hybrid combinations, it is therefore necessary to determine whether Rf5 and Rf6 can restore the fertility of HL-type japonica CMS lines. Here, we genetically characterized HL-type japonica CMS lines and the ability of Rf5 and Rf6 to restore fertility for breeding HL-type japonica hybrids. I2-KI pollen staining revealed that HL-type japonica CMS lines and their derived testcross F1 hybrids had stained abortive pollen grains, unlike HL-type indica CMS lines. Crossing experiments showed that Rf5 and Rf6 partially restored the fertility of HL-type japonica CMS lines, and Rf6 showed higher restorability than Rf5. Furthermore, we found that there were additive and dosage effects of Rf5 and Rf6 with respect to fertility restoration in HL-type japonica CMS lines. These results give critical insight into the breeding of HL-type japonica CMS lines and restorers, which will be helpful for the development of commercial HL-type japonica hybrids.

Assessment of the effect of aerotechnogenic pollution on male reproductive organs Convolvulus arvensis L.

The article presents the results of assessing the impact of airtechnogenic pollution on the male generative organs of Convolvulus arvensis L. The unfavorable effect of toxic emissions from the landfill of municipal solid waste and vehicles on the processes of microsporogenesis of the populations of Convolvulus arvensis L., which was expressed in the production of large abortive pollen, was established. It is recommended to use the male generative system of the populations of Convolvulus arvensis L. for bioindication of the quality of the state of the environment.

Influence of vehicle emissions on the male generative system of Aesculus hippocastanum L.

The article presents the results of a study of the impact of vehicle emissions on populations of Aesculus hippocastanum L. growing along roads with different traffic intensities. It was found that in areas of heavy vehicle traffic there is an increased level of abortive pollen production. Plant populations increasing the formation of damaged gametes with increasing anthropogenic load on phytocoenoses can be used for phytoindication of the environmental pollution degree. In areas with heavy traffic, pollutants have an average toxic effect on the gametogenesis of Aesculus hippocastanum L. The quality and degree of damage to the pollen zone formed by plants can serve as a bio-test of the mutagenic effect of environmental factors that have a modifying effect on male gametophyte of higher plants.

PALINOMORPHOLOGICAL AND PALINOTOXICAL ASSESSMENT OF AEROTECHNOGENIC POLLUTION IN URBOEKOSISTEMS

The men's generative system of populations of Salix babylonica growing along roads with various level of pollution was investigated. It is established that emissions of motor transport make the adverse effect on generative bodies of Salix babylonica that is shown in the raised production of sterile pollen and its poor quality that is confirmed by exis - tence of reliable differences between the populations growing in zones with various level of aero technogenic pollution. At plants of an inspection zone quite high rate of sterility - 18% of a man's gametophyte was revealed, however production of abortive pollen had been increasing at the populations growing in zones with the average and high level of pollution by 2,7 times. Calculation of an index of sterility lack of distinctions in production of sterile man's gametes between zones with average and high pollution levels have been revealed. The obtained data allowed making the conclusion that the plants that aren't changing production of abortive pollen in process of increase in pollution are tolerant and can be recommended for gardening of urbophytocenosis. Therefore Salix babylonica is offered to use for gardening of anthropogenous phytocenosis as culture, tolerant to a technogenic stress. Indicator of the raised production of abortive pollen grains in system of environmental monitoring behind the objects of environment has been recommended to use testing various degree of anthropogenous loading.

Autophagy and Apoptosis Associated with Abortive Pollen Development in the Cytoplasmic Male-sterile Line GP1BC1-12 of Platycodon grandiflorum

Platycodon grandiflorum (balloon flower) is widely cultivated for medicinal, edible, and ornamental purposes. The cytoplasmic male-sterile line GP1BC1-12 of P. grandiflorum has been used to produce hybrids, but its mechanism of sterility has not been studied. In this work, the mechanism was evaluated by a combination of transmission electron microscopy (TEM) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay. Observations showed that autophagy and apoptosis were simultaneously present in the abortive anthers. Autophagy was indicated by the autophagic vesicles, abnormal arrangement of endoplasmic reticulum, and the vacuole’s invagination. Apoptosis was characterized by chromatin aggregation and DNA cleavage. It was concluded that programmed cell death is one of the direct reasons for cytoplasmic male sterility in P. grandiflorum. This study first noted the simultaneous presence of the features of apoptosis, microautophagy, and macroautophagy in the abortive anthers of P. grandiflorum.