The anthers of angiosperms are complex male sex organs, and their development is a precisely regulated biological process ( Pearce et al., 2015 ). During anther development, various structural and physiological changes occur, and these changes
microsporogenesis and anther development. The development of anthers is complicated. Cells in different anther tissues undergo different processes that lead to conspicuous changes in morphology and structure; these processes include meiosis in microspore mother
reproductive growth stage than during the vegetative growth phase ( Tang et al., 2012 ). Numerous studies have identified the roles of miRNAs in regulating plant male sterility primarily by inhibiting target genes that affect anther development ( Dong et al
pollen viability was low. Nonetheless, the structural events of anther development involved in petaloid-type male sterility in C. oleifera remain unknown. Therefore, in our study, we examined the anther structure and pollen morphology for a cytological
It studies the changes of endogenous hormones and polyamines in cytoplasmic male sterile non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis Makino var. communis Tsen et Lee). Results showed that the microspore was prone to being sterile when there were lack of IAA, GA and polyamines, especially Put and abundant with ZRs and ABA in the anther. The imbalance of IAA/ZRs also easily caused the anther sterile.
studied ( Chua, 2016 ; Kang et al., 2013 ; Sakunphueak et al., 2013 ; Su et al., 2012 ), reports of detailed studies on anther development, cytological features, and distribution of nutritional reserves in the anthers of I. balsamina are scarce. The
function). From the outer to the inner layers, the anther wall includes epidermis, endothecium, middle layer, and tapetum. During anther development, different anther wall cell layers undergo different developmental stages, such as vacuolation of epidermal
Abstract
Gibberellin A3 (GA3) promoted anther development and increased the amount of viable pollen in the short anther parthenocarpic mutant (sha-pat) of tomato (Lycopersicon esculentum Mill.) without inducing seeded fruits.
Anthers of L-680A', `Licato', and `Ailsa Craig' tomato (Lycopersicon esculentum Mill.) were plated on Doy's basal medium 1 to determine whether microspore developmental stage and anther length influence anther callus production. Although calli were induced at all stages of anther development, anthers containing prophase I-stage microspores produced the highest frequency of calli. Fewer calli were produced as microspores approached the uninucleate and binucleate pollen stage. Callus diameter also decreased as anther development progressed. Significantly larger calli were produced from prophase I than later-stage anthers. Time of anther harvest (morning vs. afternoon) did not significantly affect callus number or diameter. Anther and flower bud length both were significantly correlated with anther developmental stage, the number of anthers producing calli, and mean calli diameter. In each case, anther length exhibited a significantly better correlation than bud length.
External “morphological characteristics of catkins from one protogynous (`Stuart') and one protandrous (`Desirable') cultivar of pecan [Carya illinoensis Wangenh.) C. Koch] were examined to define markers of cellular differentiation in the anthers. The angle between the catkin rachis and the bract, visibility of the bracteole, rachis, and anther, and anther color proved to be markers by which development could be categorized into five stages. `Stuart' catkins with bracts as the only externally visible portion of the floret (Stage I) commonly had two locules in each anther lobe. When bracteoles became externally visible (Stage II), cellular specialization had occurred to form a central core containing reproductive cells and tapetal cells differentiated and separated from the exterior layers of the anther wall. Disintegration of tapetal cells and thickening of endothecium eel! walls occurred as the angle between the rachis and bract increased to 45° (Stage III). The anther wall was reduced to only two cell layers, epidermis and endothecium, as the anthers became visible (Stage IV). The pollen grains were mature when the anthers developed a yellowish tinge (Stage V) just before anther dehiscence. Tapetal cells had developed distinguishing traits in anthers of Stage I `Desirable' catkins and endothecial cells of Stage II. Internal anther development was similar for both cultivars from Stages III-V. Trichomes, a common feature-on the surface of the staminate floral parts, became less dense with proximity of the floral parts to the interior of the floret and with catkin maturity.