Sexual dimorphism and fruit production in a dioecious understory tree, Ilex opaca Ait.

Oecologia ◽  
1991 ◽  
Vol 85 (3) ◽  
pp. 381-388 ◽  
Author(s):  
D. E. Carr
2020 ◽  
Vol 147 (3) ◽  
Author(s):  
Martin L. Cipollini ◽  
N. Royce Dingley ◽  
Patrick Felch ◽  
Natalie J. Bailey ◽  
John Patten Moss ◽  
...  

Botany ◽  
2014 ◽  
Vol 92 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Veronika L. Wright ◽  
Marcel E. Dorken

Sexual dimorphism in reproductive costs between females and males in dioecious plants is associated with divergent morphologies, life histories, and physiologies between the sexes. In Sagittaria latifolia Willd. (Alismataceae), a previous experiment has shown that sexual reproduction imposes asymmetric costs for females vs. males, with greater biomass costs for females and greater nitrogen costs for males. Here we investigate whether sexual dimorphism in nitrogen expenditure for reproduction influences the nitrogen content of leaves under natural conditions and, if so, whether it is associated with differences in photosynthetic rates between the sexes. As expected, we found significantly lower leaf nitrogen content among males compared with females and a positive association between leaf nitrogen content and photosynthetic rates. However, this difference in nitrogen content between the sexes was not associated with different photosynthetic rates for females vs. males. Our study demonstrates that an underlying difference in nitrogen content between the sexes is maintained during flower and fruit production in a natural population, but, at least at the site used for this study, this difference was not associated with divergent photosynthetic rates.


Author(s):  
I. R. Khuzina ◽  
V. N. Komarov

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.


2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.


2018 ◽  
Vol 5 (2) ◽  
pp. 60-67 ◽  
Author(s):  
Dwi Yulianto ◽  
Retno Nugroho Whidhiasih ◽  
Maimunah Maimunah

ABSTRACT   Banana fruit is a commodity that contributes a great value to both national and international fruit production achievement. The government through the National Standardization Agency establishes standards to maintain the quality of bananas. The purpose of this Project is to classify the stages of maturity of Ambon banana base on the color index using Naïve Bayes method in accordance with the regulations of SNI 7422:2009. Naive Bayes is used as a method in the classification process by comparing the probability values generated from the variable value of each model to determine the stage of Ambon banana maturity. The data used is the primary data image of 105 pieces of Ambon banana. By using 3 models which consists of different variables obtained the same greatest average accuracy by using the 2nd model which has 9 variable values (r, g, b, v, * a, * b, entropy, energy, and homogeneity) and the 3rd model has 7 variable values (r, g, b, v , * a, entropy and homogeneity) that is 90.48%.   Keywords: banana maturity, classification, image processing     ABSTRAK   Buah pisang merupakan komoditas yang memberikan kontribusi besar terhadap angka produksi buah nasional maupun internasional. Pemerintah melalui Badan Standarisasi Nasional menetapkan standar untuk buah pisang, menjaga mutu  buah pisang. Tujuan dari penelitian ini adalah klasifikasi tahapan kematangan dari buah pisang ambon berdasarkan indeks warna menggunakan metode Naïve Bayes  sesuai dengan SNI 7422:2009. Naive bayes digunakan sebagai metode dalam proses pengklasifikasian dengan cara membandingkan nilai probabilitas yang dihasilkan dari nilai variabel penduga setiap model untuk menentukan tahap kematangan pisang ambon. Data yang digunakan adalah data primer citra pisang ambon sebanyak 105. Dengan menggunakan 3 buah model yang terdiri dari variabel penduga yang berbeda didapatkan akurasi rata-rata terbesar yang sama yaitu dengan menggunakan model ke-2 yang mempunyai 9 nilai variabel (r, g, b, v, *a, *b, entropi, energi, dan homogenitas) dan model ke-3 yang mempunyai 7 nilai variabel (r, g, b, v, *a, entropi dan homogenitas) yaitu sebesar 90.48%.   Kata Kunci : kematangan pisang,  klasifikasi, pengolahan citra


2019 ◽  
Author(s):  
Marcia Hiriart ◽  
Myrian Velasco ◽  
Marcia Hiriart

2018 ◽  
Vol 14 (1) ◽  
pp. 10-24
Author(s):  
V. N. Fursov ◽  
L. S. Cherney

Darkling beetle Zophobas atratus (Coleoptera, Tenebrionidae) is recorded here for the first time as a new species for the fauna of Ukraine. Detailed study on morphology of preimaginal stages and biology of this species recently introduced to Ukraine, is given here. Zophobas atratus is an important species being easily reared in laboratory cultures and widely distributed in North and South America, Europe, and Asia. Detailed descriptions of all life stages, including egg, young and older larvae, pupa and adult of Z. atratus are required for further taxonomical study of the genus Zophobas, which isn’t yet definitively established. New identification keys for adults and larvae of the genera of tribe Tenebrionini are presented here, based on a comparative analysis of the taxonomic characters of adults and larvae of Z. atratus and species from the genera Tenebrio and Neatus. Comparative analysis of morphology of larva of Z. atratus and larvae of the tribe Cteniopodini of close subfamily Alleculinae was conducted here. The subfamily Alleculinae previously had the rank of family Alleculidae, but our analysis confirmed the reliability of its current taxonomic position as subfamily. The study of morphology of larvae of 1st and 2nd instars of Z. atratus revealed that they are characterized by special taxonomic structures that are not characteristic for oldest instars of larvae of Z. atratus. These characters include absence of spines on caudal segment, presence of a set of 4 setae at posterior margin of tergites of prothorax, metathorax, and 1st to 8th abdominal segments, strongly convex 2nd antennal segment and sensory zone in the form of an open ring on its apex, and etc. Moreover, structure of antenna of larvae of Z. atratus is similar to that of oldest larvae of most species of darkling beetles of the fauna of Ukraine. The most distinctive features of Z. atratus are: sexual dimorphism in structure of clypeus of adults; filiform sclerotized antenna of larva with a continuous sensory zone at apex of 2nd segment, weakly developed 3rd segment; fusion of sclerotized pleurites of 1st–8th abdominal segments with their tergites; sexual dimorphism in structure of 9th abdominal segment of pupa, and presence of two hooks on apex of its appendages. The data of original study of features of life cycle of Z. atratus are given. The pictures and photos of details of morphology of egg, larvae, pupa and adult of Z. atratus are presented. It was recored that life cycle of Z. atratus from laying of egg to the emergence of adult continues from 169 up to 181 days. Adults lived maximum up to 206 days. Maturation of eggs in female after copulation continues 10-11 days. Stage of egg continues 7 days, larva – up to 151 days, including pre-pupal period from 6 to 22 days, pupa – from 8 to 21 days. Twelve larval stages of Z. atratus were recorded in laboratory culture.


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