Deep learning for image-based large-flowered chrysanthemum cultivar recognition

Background Cultivar recognition is a basic work in flower production, research, and commercial application. Chinese large-flowered chrysanthemum (Chrysanthemum × morifolium Ramat.) is miraculous because of its high ornamental value and rich cultural deposits. However, the complicated capitulum structure, various floret types and numerous cultivars hinder chrysanthemum cultivar recognition. Here, we explore how deep learning method can be applied to chrysanthemum cultivar recognition. Results We propose deep learning models with two networks VGG16 and ResNet50 to recognize large-flowered chrysanthemum. Dataset A comprising 14,000 images for 103 cultivars, and dataset B comprising 197 images from different years were collected. Dataset A was used to train the networks and determine the calibration accuracy (Top-5 rate of above 98%), and dataset B was used to evaluate the model generalization performance (Top-5 rate of above 78%). Moreover, gradient-weighted class activation mapping (Grad-CAM) visualization and feature clustering analysis were used to explore how the deep learning model recognizes chrysanthemum cultivars. Conclusion Deep learning method applied to cultivar recognition is a breakthrough in horticultural science with the advantages of strong recognition performance and high recognition speed. Inflorescence edge areas, disc floret areas, inflorescence colour and inflorescence shape may well be the key factors in model decision-making process, which are also critical in human decision-making.

Evaluation of different Gerbera Cultivars for Growth and Flower Characteristics under Naturally Ventilated Polyhouse under Nagaland Condition

ABSTRACT On- farm trail was conducted in Longleng district of Nagaland during 2016-17 to compare the phonological development and production potential of four varieties of gerbera viz. Silvester, Stanza, Rosalin and Brilliance at farmers field under naturally ventilated polyhouse conditionin Longleng District of Nagaland. Result revealed that Rosalin recorded maximum leaf length (49.68 cm), plant spread (57.82 cm), flower diameter (12.04 cm), diameter of trans floret (7.52 cm), diameter of disc floret (3.4 cm), Peduncle diameter (0.8 cm), length of ray floret (5.44 cm), width of ray floret (1.12 cm), whereas Stanza recorded maximum leaf breadth (19.76 cm), no. of ray floret (73.4 nos.), vase life (13.2 days), Silvester recorded maximum in plant height (52.04 cm), no. of leaf/plant (19.6 nos.) and no. of suckers /plant (2.2 nos.), no. of flowers/plant (8.4 nos.) and Brilliance recorded maximum Peduncle length (70.96 cm). Vase life of flower was recorded significantly higherin Stanza (13.2 days) as compared to other cultivars and minimum with Brilliance (10.8 days). Rosalin and Stanza appears to be the best cultivars under Longleng climatic condition as compared to Silvester and Brilliance in terms of vegetative growth and flowering quality characters.

Pollination ecology of Synedrella nodiflora (l.) Gaertn. (Asteraceae)

Synedrella nodiflora (L.) Gaertn grows almost throughout the year if the soil is damp. It produces heterogamous capitula with female ray florets anthesing first day and bisexual disc florets anthesing on the next three consecutive days. Disc florets are dichogamous, herkogamous, self-compatible, self-pollinating (vector-mediated) and display secondary pollen presentation through an intermediate form of brush mechanism. Ray and disc florets exhibit facultative xenogamy. Butterflies are principal pollinators while bees, wasps and flies are supplementary pollinators. Thrips, Microcephalothrips abdominalis uses the florets as breeding and feeding sites; the feeding activity effects pollination. The ray and disc florets produce cypselas; the cypselas produced by ray florets are heavier, elliptical, membranous with upwardly-pointing teeth along the margins and 2 short terminal awns while those produced by disc floret are lighter, cylindrical and tangentially compressed with 2 or 3 stiff terminal divaricate awns. Seed dispersal is polychorous and represented by anemochory, anthropochory, zoochory and ombrohydrochory. Cypselas of ray florets disperse to short distances and germinate germinate under specific germination conditions either at parental sites or in similar habitats while those of disc florets disperse farther away from parental sites and germinate readily under a wide range of conditions. Therefore, bimorphic cypselas with different germination abilities enable the plant to grow as a widespread weed but not as an invasive weed.

A CYCLOIDEA-like gene mutation in sunflower determines an unusual floret type able to produce filled achenes at the periphery of the pseudanthium

The pseudanthium of sunflower (Helianthus annuus L.) consists of two floret types: zygomorphic sterile ray florets and actinomorphic hermaphrodite disc florets. In the tubular ray flower (turf) mutant, the loss-of-function of a CYCLOIDEA (CYC) gene generates hermaphrodite tubular-like ray florets that replace the normal sterile ray florets. We evaluated whether tubular-like ray florets have a multifaceted set of floral traits and the presence of heteromorphic seeds in the turf inflorescence. During early stages of floral ontogeny, primordia of both tubular-like ray florets and typical ray florets displayed a comparable shape. In contrast, during later stages of development, the form of tubular-like ray floret primordia was most similar to disc floret primordia. In mature tubular-like ray florets, corolla and ovary had both ray and disc floret characteristics but also displayed distinct identity traits. In open-pollinated tubular-like ray florets, the seed set was low, but a noteworthy increase of filled achenes was obtained by hand pollination. Wild type ray achenes were always empty. Embryos of tubular-like ray florets were shorter and lighter than the embryos of disc florets but able to produce fertile plants. In conclusion, the different identity characteristics combined in tubular-like ray florets of the mutant evolved a capitulum type not described in the genus Helianthus.

Reproductive Development in Pink Tickseed, Coreopsis rosea, Nutt.

Landscape and garden use of Coreopsisrosea has been growing recently. With the introduction of the new varieties of Coreopsisrosea `Sweet Dreams' and `Limerock Ruby', there are increased opportunities for commercial sales. While plants can be propagated by vegetative means, seed production is generally less expensive, seed can be stored, and hybrid development depends on seed production. As a result, it is beneficial to understand the reproductive process of the plant. The purpose of this research was to investigate the reproductive development of Coreopsisrosea. This research also seeks to identify, describe and record inflorescence morphological characters, which could be useful in plant systematic and phylogeny studies. To this end, the anthesis process of pink tickseed, Coreopsisrosea Nutt., was studied in 100 inflorescences from 10 plants. Inflorescences were tagged when they were first visible and measured daily for a month. The following measurements were taken: number of ray flowers, inflorescence diameter, diameter of the disc floret cluster (head), timing of anthesis, presence of pollen, and the longevity of opened flowers. The inflorescence anthesis process was 19.8 (±1.6) days long and was subdivided into 13 stages of development. During the 20 days of inflorescence anthesis, the flower was open 27.5% of the time (5.4 days). When the disc florets started to open, they did so from the outer layer of the cluster to the center of the cluster; therefore, florets in the head did not mature at the same time. Micrographs were taken using a dissecting microscope (Cobra dynascope) to illustrate the entire process.

A multivariate morphometric study of Solidago nemoralis (Compositae: Astereae) and comparison with S. californica and S. sparsiflora

Multivariate analysis of 11 quantitative morphological characteristics of 177 individuals of the Solidago nemoralis complex supports recognition of two subspecies. In a cluster analysis, two groups were immediately obvious (corresponding approximately to ssp. decemflora and ssp. nemoralis); within the ssp. nemoralis cluster, diploids and tetraploids tended to cluster separately. Discriminant analyses were performed on two and three a priori groups. The prairie and open savannah race ssp. decemflora could be distinguished from the eastern ssp. nemoralis son the basis of corolla lobe length, ray floret pappus length, numbers of disc florets, involucre height, and the lengths of the disc corolla, disc corolla limb, and disc floret pappus. Capitulescence form was found to be plastic and of limited taxonomic value. Plants with elongated ascending lower capitulescence branches (elm tree shaped) occurred throughout much of the range of ssp. nemoralis; these have been treated previously as var. or ssp. haleana, but are placed in synonymy. A late glacial and postglacial history of S. nemoralis is hypothesized. In a second set of analyses, small samples of S. nemoralis, S. californica, and S. sparsiflora were compared. Based on the floral characters used, the two subspecies of S. nemoralis differed to a greater degree than S. californica and S. sparsiflora differed from each other. The latter two differed from each other on vegetative traits more so than did the two subspecies of S. nemoralis. The need for a larger study of S. californica, S. sparsiflora, S. velutina, and related taxa was indicated.