Morpho-Anatomy of the Gynoecium and Fruit in Three Ornamental Members of Campanuloideae (Campanulaceae)

Gynoecium and fruit micromorphology and anatomy were studied using light microscopy in three species of Campanuloideae belonging to the tribes Cyanantheae ( Platycodon grandiflorus ), Wahlenbergieae ( Jasione montana ), and Campanuleae ( Adenophora liliifolia ) of the native and cultivated flora of Ukraine, to elucidate structural adaptations for fruit dehiscence. The studied species differed in flower/fruit orientation, carpel number, ovary insertion, and capsule-opening position, and the information provided a background for the discovery of common anatomical features influencing fruit dehiscence. In the studied species, the synascidiate and symplicate zones in the ovary and prominent placentae were found to be located near the mid-region of the ovary. The distinct innervation of the ovary wall and ovules was described. In P. grandiflorus , the septa and fruit wall contained a lignified parenchyma in a subepidermal position, while in J. montana and A. liliifolia , lignification was observed only in proximal portions of the septa, above the placenta ( J. montana ), or was noted as a narrow strand from the ovary base to the mid-region, called “axicorn” ( A. liliifolia ). In all the studied species, unlignified endocarpium was detected. The semi-inferior capsule of P. grandiflorus has been defined as a capsule of the Forsythia -type, with a sclerenchymatous layer in the inner zone of the mesocarpium. In J. montana and A. liliifolia , a new histogenetic type of capsule is described as Campanula -type, without lignified layers in the fruit wall and with lignified tissue in the septa, which enabled dehiscence. Our study proposed for the first time the classification of the capsules found in the studied species based on the development of openings in the superior or inferior regions of the fruits. The upright fruits of P. grandiflorus and J. montana reveal incomplete dorsiventral dehiscence in the superior region of the fruit, while dehiscence of pendent fruits of A. liliifolia is hippocrepiform-septifragal interlocular and occurs in the inferior region of the fruit at its base, as revealed previously in Campanula latifolia fruit.

Studies on the phenology of some terrestrial orchids of Western Ghats, India

The present paper describes the distribution, natural habitat and phenology of some terrestrial orchids in Shimoga district, Karnataka. The phenophases viz., leafing, flowering, fruiting, fruit dehiscence are observed for 25 orchid taxa belonging to 13 genera in Shimoga district. They are Dienia ophrydis (J. Koenig) Seidenf., Disperis zeylanica Trimen., Epipogium roseum (D. Don) Lindl., Eulophia spectabilis (Dennst.) Suresh., Geodorum densiflorum (Lam.) Schltr., Habenaria crinifera Lindl., Habenaria elwesii Hook f., Habenaria furcifera Lindl., Habenaria grandifloriformis Blatt. & Mc Cann., Habenaria heyneana Lindl., Habenaria longicorniculata J. Graham., Habenaria multicaudata Sedgw., Habenaria plantaginea Lindl., Liparis deflexa Hook. f., Liparis odorata (Willd) Lindl., Malaxis versicolor (Lindl.) Abeyw., Nervilia concolor (Blume) Schltr. Nervilia crociformis (Zoll. & Moritzi) Seidenf., Nervilia infundibulifolia Blatt. & Mc Cann., Nervilia plicata (Andrews) Schltr., Pecteilis gigantea (Sm.) Raf.. Peristylus plantagineus (Lindl.), Peristylus spiralis A. Rich., Satyrium nepalense D. Don, Zeuxine longilabris (Lindl.) Trimen. Phenology is the timing of plant life cycle events. Regular field visits were carried to observe the different life events. Most of the terrestrial orchids complete their life cycle in April to September or October month. The present research gives additional phenological aspects of terrestrial orchids in Shimoga district. Vegetative phenology is important to understand the ecology and instinct history of a plant species and may help to develop the conservation strategies of endangered species.

A water drop-shaped slingshot in plants: geometry and mechanics in the explosive seed dispersal of Orixa japonica (Rutaceae)

Background and Aims In angiosperms, many species disperse their seeds autonomously by rapid movement of the pericarp. The fruits of these species often have long rod- or long plate-shaped pericarps, which are suitable for ejecting seeds during fruit dehiscence by bending or coiling. However, here we show that fruit with a completely different shape can also rely on pericarp movement to disperse seeds explosively, as in Orixa japonica. Methods Fruit morphology was observed by hard tissue sectioning, scanning electron microscopy and micro-computed tomography, and the seed dispersal process was analysed using a high-speed camera. Comparisons were made of the geometric characteristics of pericarps before and after fruit dehiscence, and the mechanical process of pericarp movement was simulated with the aid of the finite element model. Key Results During fruit dehydration, the water drop-shaped endocarp of O. japonica with sandwich structure produced two-way bending deformation and cracking, and its width increased more than three-fold before opening. Meanwhile the same shaped exocarp with uniform structure could only produce small passive deformation under relatively large external forces. The endocarp forced the exocarp to open by hygroscopic movement before seed launching, and the exocarp provided the acceleration for seed launching through a reaction force. Conclusions Two layers of water drop-shaped pericarp in O. japonica form a structure similar to a slingshot, which launches the seed at high speed during fruit dehiscence. The results suggest that plants with explosive seed dispersal appear to have a wide variety of fruit morphology, and through a combination of different external shapes and internal structures, they are able to move rapidly using many sophisticated mechanisms.

A new species of Mimosa section Mimosa (Leguminosae) from the Paraguayan Cerrado

Mimosa schininii (Leguminosae), a new species from the Amambay region, in the Cerrado ecoregion of northeastern Paraguay, is described and illustrated. This new species belongs to Mimosa L. section Mimosa series Mimosa subseries Brevipedes Barneby, and is similar to M. brevipes Benth. and M. sceptrum Barneby, but differs from them by shorter inflorescence, secondary leaflets venation pattern and fruit dehiscence. This new entity resembles, in some characters, other subseries of series Mimosa, such as Mimosa section Mimosa series Mimosa subseries Pedunculosae (Benth.) Barneby and Hirsutae (Benth.) Barneby, but can be distinguished adequately from them by vegetative, floral, and carpological characters. Illustration, distribution map, and a key to distinguish M. schininii from close relatives are provided.

To pupate or not to pupate: a case study of an obligate pollination mutualism in Glochidion ferdinandi (Phyllanthaceae) and Epicephala colymbetella (Gracillariidae)

Obligate pollination mutualisms have recently been recorded in the Glochidion genus with Epicephala moth associates (leaf-flower and leaf-flower moths). There is limited literature on Australian Glochidion species and their pollinators. Glochidion ferdinandi occurs predominantly across the east coast of Queensland, Australia and has an obligate pollination association with Epicephala colymbetella. Early descriptions of G. ferdinandi describe the encapsulation of the adult moth within the fruit. In the present study, observations and fruit dissections were recorded to analyse the role of symbionts within this mutualism, pollinator life history and the flowering phenology of the host. Our study confirmed this rare behaviour in which E. colymbetella pupated within G. ferdinandi fruit in which adult moths were retained until fruit dehiscence. Fruit dissections identified two other species alongside E. colymbetella, a seed consuming Spilomelinae moth and parasitoid Bracon wasp. Although both moth species were found to reduce the number of surviving ovules in the fruit, E. colymbetella also provided a pollination benefit to G. ferdinandi. Furthermore, the life histories of E. colymbetella and phenology of G. ferdinandi were observed to be highly synchronous, with larvae developing concurrently with ovules after flower fertilisation. Retention of the adult moth in fruit has only previously been recorded in one other Epicephala (lanceolaria).

Pod Shattering: A Homologous Series of Variation Underlying Domestication and an Avenue for Crop Improvement

In wild habitats, fruit dehiscence is a critical strategy for seed dispersal; however, in cultivated crops it is one of the major sources of yield loss. Therefore, indehiscence of fruits, pods, etc., was likely to be one of the first traits strongly selected in crop domestication. Even with the historical selection against dehiscence in early domesticates, it is a trait still targeted in many breeding programs, particularly in minor or underutilized crops. Here, we review dehiscence in pulse (grain legume) crops, which are of growing importance as a source of protein in human and livestock diets, and which have received less attention than cereal crops and the model plant Arabidopsis thaliana. We specifically focus on the (i) history of indehiscence in domestication across legumes, (ii) structures and the mechanisms involved in shattering, (iii) the molecular pathways underlying this important trait, (iv) an overview of the extent of crop losses due to shattering, and the effects of environmental factors on shattering, and, (v) efforts to reduce shattering in crops. While our focus is mainly pulse crops, we also included comparisons to crucifers and cereals because there is extensive research on shattering in these taxa.

Pod Shattering: A Homologous Series of Variation Underlying Domestication and an Avenue for Crop Improvement

In wild habitats, fruit dehiscence is a critical strategy for seed dispersal; however, in cultivated crops it is one of the major sources of yield loss. Therefore, indehiscence of fruits, pods, etc., was likely to be one of the first traits strongly selected in crop domestication. Even with the historical selection against dehiscence in early domesticates, it is a trait still targeted in many breeding programs, particularly in minor or underutilized crops. Here, we review of this trait in pulse (grain legume) crops, which are of growing importance as a source of protein in human and livestock diets, and which have received less attention than cereal crops and the model plant Arabidopsis thaliana. We specifically focus on the i) history of indehiscence in domestication across legumes, ii) structures and the mechanisms involved in shattering, iii) the molecular pathways underlying this important trait, iv) an overview of the extent of crop losses due to shattering, and the effects of environmental factors on shattering, and, v) efforts to reduce shattering in crops. While our focus is mainly pulse crops, we also included comparisons to crucifers and cereals because there is extensive research on shattering in these taxa.