Assessment of weather effect on flower morphogenesis and fruit set in mango varieties in central India

A two-year field experiment was initiated in 2017-18 and 2018-19 years simultaneously to assess temperature on flower morphogenesis stages, flower sex ratio (hermaphrodite/staminate male flower) and fruit set in monoembryonic Langra and Amrapali varieties. Different dates of flower phenological stages viz., bud, panicle, bloom and flower initiation, pea, marble, egg, and maturity of fruits were recorded. The Langra variety exhibited bud initiation after mid December whereas Amrapali variety by the end of December. The range of mean maximum / minimum temperature as 26-31/10-12 °C promoted hermaphrodite flowers per panicle by 74 per cent in Langra variety, whereas range of 27-29/11-13 °C favored by 35 per cent in Amrapali variety. A positive and significant correlation between total number of flower / panicle and flower sex ratio in both the varieties suggested that higher temperature during initial flower phenologies improved number of hermaphrodite flowers. A mean minimum temperature for producing more number of hermaphrodite flower exhibited a range of 11-14 °C under central Indian conditions. Fruit set was maximum during pea stage and decline afterwards in marble and fruit maturity stages due to sudden rise in temperature at marble stage that caused in drop down of humidity thereby resulted in fruit drop in both the varieties.

Identification of developmentally important genes in Silene latifolia through chemical genetics and transcriptome profiling

Dioecious plants possess diverse sex determination systems and unique mechanisms of reproductive organ development; however, little is known about how sex-linked genes shape the expression of regulatory cascades that lead to developmental differences between sexes. In Silene latifolia, a dioecious plant with stable dimorphism in floral traits, early experiments suggested that female-regulator genes act on the factors that determine the boundaries of the flower whorls. To identify these regulators, we sequenced the transcriptome of male flowers with fully developed gynoecia induced by rapid demethylation in the parental generation. As the hermaphrodite flower trait is holandric (transmitted only from male to male, inherited on the Y chromosome), we screened for genes that are differentially expressed between male, female, and hermaphrodite flowers. Dozens of candidate genes that are upregulated in hermaphrodite flowers compared to male and female flowers were detected and found to have putative roles in floral organization, affecting the expression of floral MADS-box and other genes. Amongst these genes, eight candidates were found to promote gynoecium formation in female and hermaphrodite flowers, affecting organ size, whorl boundary, and the expression of mainly B class flower genes. To complement our transcriptome analysis, we closely examined the floral organs in their native state using a field emission environmental scanning electron microscope. Our results reveal the principal regulatory pathways involved in sex-specific flower development in the classical model of dioecy, S. latifolia.

Determination of a sex-related RAPD marker in Carob (Ceratonia siliqua L.)

Molecular markers are used in the characterization and breeding of organisms. Carob (Ceratonia siliqua L.) is a species with both dioecious and hermaphrodite flower forms. The determination of sex at an early stage of growth in this species, whose juvenility period is long, is important in breeding studies. The objective of this study was to identify the sex-related markers using RAPD method. Ten genotypes were obtained from natural F1 hybrids between a naturally grown a female and a male carob tree. DNA was extracted from the leaves of 12 carob plants. Using BSA, the female and male bulks were formed from five female and five male plants, respectively, using equal amounts of DNA from each plant. In this study, 130 RAPD primers were tested. That of 21 primers tested showed polymorphisms between male and female bulks. While the fragment of 750 bp from the OPA17 RAPD primer was not detected in the female parent, female bulk, and female F1 hybrids; it was observed in the male parent and four out of five male F1 hybrids. This is the first report in the literature that one RAPD marker, namely OPA17-750, related to 80% reliability to male sex in carob was determined.

Differentially Expressed Genes Shared by Two Distinct Cytoplasmic Male Sterility (CMS) Types of Silene vulgaris Suggest the Importance of Oxidative Stress in Pollen Abortion

Cytoplasmic male sterility (CMS), encoded by the interacting mitochondrial and nuclear genes, causes pollen abortion or non-viability. CMS is widely used in agriculture and extensively studied in crops. Much less is known about CMS in wild species. We performed a comparative transcriptomic analysis of male sterile and fertile individuals of Silene vulgaris, a model plant for the study of gynodioecy, to reveal the genes responsible for pollen abortion in this species. We used RNA-seq datasets previously employed for the analysis of mitochondrial and plastid transcriptomes of female and hermaphrodite flower buds, making it possible to compare the transcriptomes derived from three genomes in the same RNA specimen. We assembled de novo transcriptomes for two haplotypes of S. vulgaris and identified differentially expressed genes between the females and hermaphrodites, associated with stress response or pollen development. The gene for alternative oxidase was downregulated in females. The genetic pathways controlling CMS in S. vulgaris are similar to those in crops. The high number of the differentially expressed nuclear genes contrasts with the uniformity of organellar transcriptomes across genders, which suggests these pathways are evolutionarily conserved and that selective mechanisms may shield organellar transcription against changes in the cytoplasmic transcriptome.

Status of Pepper Farming and Flower Composition of Different Pepper Varieties in Sarawak

Pepper (Piper nigrum L.) is one of the most important cash crops in Sarawak. The productivity of pepper is consistently low due to the low yield of berry production. One of the major problems of pepper production is inconsistent flowering time. This is due to the morphology and inheritance of functional male, female and hermaphrodite (bisexual) flower in P. nigrum which affect the productivity of pepper. For the exploitation of pepper for its maximum production, the detailed of flower development and flower composition are important factors to be considered. A field survey was conducted to determine the status of farming practices and problems encountered by the farmers. The study was also done to determine the composition of flower which influenced the consistency of berry production in P. nigrum in Sarawak. Surveys were conducted at 18 pepper farms in Sarawak to determine the composition of flowers in different types of Sarawak pepper varieties which are Kuching, Semenggok Aman and Semenggok Emas. Nine spikes were harvested in each pepper vine. Three pepper vines were selected randomly for each variety. The spikes were then observed under 3D Keyence microscope to determine the number of flowers of each type of flower. The survey on the farming practices were also conducted. The composition of flower was found to be varied between varieties. ‘Kuching’ variety had less hermaphrodite flower when compared to ‘Semenggok Aman’ and ‘Semenggok Emas’ varieties. In addition, a proportion of 29% farmers had encountered root rot disease problem in their farm, while 21% stated that unsynchronisation of berries production in each harvesting time as a major problem.

Pollen viability and floral biology of Mandacaru (Cereus jamacaru (DC) (Cactaceae))

Pollen fertility is indicated by viability, which influences the reproductive success of plants. Mandacaru is a native tree species with natural distribution in the Caatinga. The objective was to verify the pollen viability, pollen per ovule ratio and the morphological identification of the mandacaru flower (Cereus jamacaru). Ten flower buds were used and one hundred anthers of these buds, which and stained with Alexander dye on checkered glass slide and viable and non-viable pollens were accounted amount of ovule per flower bud was counted the pollen/ovule ratio. Mandacaru presented viability of 99.41% the pollen, with an average of 314,686 pollens on each flower. There were 356 pollens for each ovule, this indicates the species reproductive system for facultative autogamous and facultative xenogamics. The flower is hermaphrodite, with gynoecium measuring an average of 160.9 mm, an average of 883 ovules per flower, the androecium averaging 577 anthers per flower, 545 pollen per anther. Mandacaru has high pollen viability, with large size hermaphrodite flower, with high number of anthers and pollen contained in these anthers.

PEWARISAN SIFAT HERMAPRODIT DAN KONTRIBUSINYA TERHADAP DAYA HASIL PADA JARAK PAGAR (Jatropha curcas L.)

<p>ABSTRAK<br />Kontribusi sifat hermaprodit terhadap daya hasil tanaman jarak<br />pagar belum banyak diketahui. Tujuan penelitian adalah mengetahui peran<br />bunga hermaprodit terhadap daya hasil dan mekanisme pewarisannya.<br />Penelitian dilakukan terhadap 60 genotipe jarak pagar di Kebun Percobaan<br />Balittri Sukabumi. Penelitian dilaksanakan mulai bulan Mei 2007 sampai<br />dengan Juli 2010. Jarak tanam 2 m x 2 m, menggunakan 2,5 kg pupuk<br />kandang + 20 g Urea + 20 g SP 36 + 10 g KCl per tanaman. Penelitian<br />terdiri dari (1) evaluasi tipe bunga jarak pagar dan (2) pewarisan sifat<br />hermaprodit dan kontribusinya terhadap daya hasil. Hasil evaluasi<br />menunjukkan bahwa delapan dari 60 genotipe jarak pagar yang dievaluasi<br />merupakan tanaman tri-monoecious yang menghasilkan bunga jantan,<br />bunga betina, dan bunga hermaprodit, 52 lainnya merupakan tanaman<br />monoecious yang hanya menghasilkan bunga jantan dan bunga betina.<br />Karakter yang dimiliki oleh delapan genotipe tri-monoecious yang<br />dievaluasi adalah lebih lambat berbunga (mulai berbunga pada umur 120-<br />274 hari) dan berdaya hasil rendah sampai sedang (jumlah buah 23-228<br />per tanaman pada tahun pertama). Kemunculan bunga hermaprodit tidak<br />terjadi sepanjang tahun, tetapi lebih dominan pada tanaman berumur enam<br />bulan. Persentase bunga hermaprodit berkisar 6,25-53% dari total bunga<br />yang dihasilkan. Persentase fruitset pada tandan bunga hermaprodit lebih<br />tinggi dibanding tandan bunga non-hermaprodit, dengan tingkat<br />keberhasilan rata-rata 80% (kisaran 56-100%). Pada tandan bunga yang<br />tidak menghasilkan bunga hermaprodit, buah jadi rata-rata sebesar 50%<br />(kisaran 11-100%). Daya hasil tanaman jarak pagar ditentukan oleh<br />genetik tetua. Bunga hermaprodit diwariskan oleh tetua betina maupun<br />tetua jantan. Gen pengendali sifat hermaprodit diduga adalah gen<br />sederhana yang bersifat dominan.<br />Kata kunci: Jatropha curcas, monoecious, tri-monoecious, bunga<br />hermaprodit, fruit set</p><p>ABSTRACT<br />Hermaphrodite character has been reported in physic nut, its role<br />and contribution to production process especially to the yield has not been<br />investigated. The objectives of this research were to evaluate<br />hermaphrodite flowers contribution on yield and their mechanism<br />inheritance. The evaluation was conducted at the Experimental Station of<br />Balittri Sukabumi from May 2007 to July 2010. The spacing was 2 m x 2<br />m with 2,5 kg manure + 20 g Urea + 20 g SP 36 + 10 g KCl/plant. The<br />experiment consisted of (1) evaluation of flower type of physic nut and<br />(2) hermaphrodite inheritance and their contribution on yield. Results of<br />the experiment indicated eight from 60 physic nut genotypes were tri-<br />monoecious which were capable on producing male, female, and<br />hermaphrodite flowers while as the rest (52 genotypes) were monoecious<br />which produced only male and female flowers. The tri-monoecious were<br />generally late flowering (120-274 days after planting) and low to medium<br />yield (producing 23-228 fruits per plant in the first year). Hermaphrodite<br />flowers generally occurred six months after planting at the amount ranged<br />from 6,25-53% of total flowers. Fruit set of inflorescences having<br />hermaphrodite flowers was higher, average of 80% (ranged from 56-<br />100%) than those with female and male flowers, average of 50% (ranged<br />from 11-100%). Yield of physic nut was affected by the genetic potential<br />of their parents rather than hermaphrodite character. Hermaphrodite flower<br />character was inherited by both female and male parents and might be<br />controlled by simple-dominant gene.<br />Key words: Jatropha curcas, monoecious, tri-monoecious, hermaphrodite<br />flower, fruit set</p>

Karakter Morfologi dan Sitologi Bunga Pepaya Merah Delima

The papaya plant has three types of flowering, male flowers, female flowers, and perfect flower (hermaphrodite). The difference in interest affects the shape of the resulting fruit. This study aimed to characterize morphology and cytology of papaya flowers. The study was conducted in Tropical Fruit Research Institute at Solok and Laboratory of SPT at the Biology Department of the Faculty of Mathematics and Natural Sciences, Andalas University, Padang, West Sumatra. The research material uses papaya flowers Merah Delima variety from KP. Aripan Balitbu Troipka. The results showed the male flowers of male plants were smaller than the male flowers of the perfect plant. The difference of hermaphrodite flower of pentandria with hermaphrodite elongata flower, among others, the number of stamens, the length of the stem and the size of the ovary. Hermaphrodite pentandria has a number of stamens 5 while elongata has stamens 10

Short communication: Morphological characteristics of flower and fruit in several rambutan (Nephelium lappaceum) cultivars in Serang City, Banten, Indonesia

Windarsih G, Efendi M. 2019. Morphological characteristics of flower and fruit in several rambutan (Nephelium lappaceum L.) cultivars in Serang City, Banten, Indonesia. Biodiversitas 20: 1442-1449. Indonesia is one of the centers of diversity of rambutan in the world with 22 species. Compared to other species, Nephelium lappaceum L. is mostly cultivated species. This study aimed to identify the generative morphological variation in several rambutan cultivars in the area of Serang City, Banten Province. The plant materials used were five cultivars of rambutan, Parakan, Rapiah, Aceh, Sinyonya, wild type, and male trees. In each plant, three bunches of inflorescence were taken, and then the flowers from each bunch were observed when the flowering phase was open (blooming). In addition, 3-5 fruit bunches were taken per plant, and then 3-5 fruits per bunch were observed. Based on the results obtained, it can be concluded that there is monoecious plants of rambutan (Aceh, Rapiah, wild type), and dioecious plant (male tree). In a monoecious plant, it produces the hermaphrodite flowers, whereas, in a dioecious plant, it just produces the male flowers. In the hermaphrodite flower, it is composed of pedicel, tepal, stamen, and pistil, while the male flower does not have pistil. The Aceh cultivar has the longest average fruit bunch (22.90 cm), Rapiah has highest number of fruit per bunch (15.86 fruits), Parakan has highest spine density (11.64 strands per 1x1 cm2) and longest spine (13.2 mm), Rapiah has a shortest average spine (3.4 mm) with a stiff texture, Rapiah and Aceh have a thickest of fruit rind (3.3 mm). Aceh has the largest size and weight of fruit with the fruit length 4.62 cm, fruit diameter 3.83 cm, fruit weight 37.42 g, weight of fruit rind 17.51 g, weight of aryl 17.94 g, and thickness of aryl 7.7 mm. From a dendrogram analysis, the five cultivars had a similarity distance coefficient from 40% to 69%. Parakan and Sinyonya had highest similarity distance (69%), while Aceh was separated from other cultivars with a similarity distance 40%.