Polygamous breeding system identified in the distylous genus Psychotria: P. manillensis in the Ryukyu archipelago, Japan

Distyly is a genetic polymorphism composed of long-and short-styled flowers in a population. The evolutionary breakdown of distyly has been reported in many taxa, and mainly involves a shift toward monomorphism or dioecism. However, a shift toward monoecism has not been reported in distylous species. Psychotria (Rubiaceae), one of the world largest genera, consists of distylous species and their derivatives. In our preliminary study, however, we identified some monoecious individuals in a population of Psychotria manillensis. To understand the breeding system and reproductive biology of P. manillensis, we investigated floral traits, open fruit set, and flower visitors, and performed hand pollination and bagging experiments in five populations of Okinawa and Iriomote islands, Ryukyu Islands, Japan. The populations of P. manillensis were composed mainly of monoecious individuals (54%), followed by female (30%), male (14%), and hermaphroditic (2%) individuals at the time of flower collection. Of the collected flowers, 93% were functionally unisexual (male or female), whereas only 6.5% were perfect (hermaphroditic). However, some individuals changed sex mainly towards increasing femaleness during the flowering period. Moreover, 35% of the studied plants changed their sexual expression over the years. P. manillensis showed self-compatibility and no agamospermy. The fruit set under open pollination varied among populations and years (1.8–21.9%), but it was significantly higher than that of auto-selfing (0.68–1.56%). Wasps and flies were the main flower visitors and probably the main pollinators of the species. In conclusion, P. manillensis was revealed to be polygamous, involving monoecious, female, male, and hermaphroditic individuals. This is the first report of the polygamous breeding system not only in the genus Psychotria, but also in all heterostylous taxa.

Genetic variation of Gmelina arborea Roxb in Trenggalek, East Java

White teak (Gmelina arborea Roxb) is an introduced species of the verbenaceae. This study observed genetic variation of G. arborea in Trenggalek, East Java. Incomplete Block Design was used for this trial comprising four replications, five populations, 50 families, and three tree plots with planting space of 3 x 2 m. Significant differences between seed origins for height and survival rate were exhibited in this study; however, no significant differences between populations for diameter traits at 1st year old. Meanwhile, significant differences between populations for height, diameter, and survival rate existed at second years old. The mean survival rate at first and second years old were 98, 44% and 95, 95%, height were 1.23 m and 2.86 m, and stem diameter was 2.18 cm and 3.66 cm. Moderate heritability’s showed for height and diameter were (h2 i = 0.29; h2 f = 0.30), (h2 i = 0.24; h2 f = 0, 38) and (h2 i = 0.19; h2 f = 0.30), (h2 i = 0.18; h2 f = 0.28). Genetic correlation for height and diameter were rg = 0.75, and rg = 0.89. Genetic variation growth of G. arborea progeny test can be used as basic information of the plus trees selection with good performance. Therefore, the open pollination between remaining plus tress will produce a good quality of seed, which will increase the volume of timber harvested.

The effect of parental plant and washing materials on seed germination of F2 generation apple cactus (Cereus spp.)

Apple cactus (Cereus sp.) is a genus of cactus, and two species that are often crossed are long spines (Cereus jamacaru) and short spines (Cereus peruvianus). Those species have seeds with physical dormancy, that is, seed mucilage that can inhibit the germination process. This research aims to study the effect of parental plants and washing materials on the germination of F2 apple cactus seeds. This study used two-factor RCBD using 3 parental plants of the F2 generation of apple cactus (C. jamacaru open pollination, C. peruvianus × C. jamacaru, C. jamacaru × C. peruvianus) and 5 washing materials (without washing, pH 8, distilled water (pH 7), pH 5, and pH 9) which was carried out in 3 repetitions. The results showed that seeds of the cross C. jamacaru as female parent (C. jamacaru open pollination and C. jamacaru × C. peruvianus) produced better germination than seeds from the cross of C. peruvianus as female parent (C. peruvianus × C. jamacaru). Although the washing material didn’t significantly affect the germination of F2 apple cactus seeds, there was an influence of using pH 9 to minimize seed mucilage so that the extraction process was easier.

Consequences of the high abundance of Bombus terrestris on the pollination of Vicia faba

One of the main visitors to Fabia bean crops (Vicia faba) in South America is the invasive bumblebee species Bombus terrestris. This is particularly true in Chile, where B. terrestris was first introduced in 1997 and is now common over much of the country. In this study, we evaluated the activity of the principal pollinators of V. faba over two cropping seasons by assessing their visitation rates while distinguishing between legitimate visits, likely to lead to pollination, and nectar robbery. We then determined the net contribution of insect visitation on pod and seed set. We recorded seven species of floral visitors. Most visits (legitimate visits and robbery) were from the honeybee (Apis mellifera), with B. terrestris being the next most common visitor. In the case of B. terrestris, 87.19% of visits were nectar robbery. On average, the same flower perforation was visited 23 times by B. terrestris during the flower's lifespan. In general, the frequency of legitimate visits varied with pollinator identity and year. For B. terrestris, each flower received an average of 0.95 legitimate visits during its entire lifespan. The time spent by B. terrestris visiting flowers for both nectar robbery or pollen collection decreased after the first day of flowering suggesting resource depletion. The number of pods, total seed number, and seed weight were lower where self rather than open pollination. This suggests that open pollination increased reproductive success. We conclude that B. terrestris was likely to contribute relatively little to pollination while at the same time depleting floral resources throughout the flowers’ lifespan.

GENETIC DIVERSITY AMONG MANGO HYBRIDS IN THE BRAZILIAN SEMIARID REGION1

ABSTRACT The aim of this study was to evaluate mango hybrids obtained by open pollination based on the physical and chemical traits of the fruit, and to analyze the genetic diversity among these hybrids to find plants that produce quality fruit both for direct consumption and for industrial processing. The hybrids under study were generated from seeds produced from crosses with unknown genotypes as a result of open pollination. The unknown genotypes were randomly scattered in areas dedicated to growing a Tommy Atkins variety, and plants were obtained from mango seeds generated through sexual propagation. To assess genetic diversity, cluster analysis was carried out, as well as principal component analysis. Two hybrids were most prominent in terms of fruit weight, fruit length, fruit diameter, pulp weight, and pulp yield, with mean values greater than 245 g for pulp weight and 70% for pulp yield. Regarding fiber content in the pulp, six hybrids had a score of "2", that is, moderately fibrous fruit. For acidity and soluble solids content, the hybrids exhibited variations from 0.19 to 1.06% of citric acid and from 13.1 to 20.6 ºBrix, respectively. For peel color, tones ranging from reddish orange to yellow and green were observed. As for pulp color, there was variation from orange to light yellow tones. There was variability among the mango hybrids regarding the fruit traits analyzed, and hybrids that produce fruit that combine traits of economic interest were identified.

Comparative analysis of sour cherry cultivars on their ecological and biological indicators

Sour cherries developed in the northern hemisphere, an alloploid hybrid of dwarf sour cherries (Prunus fruticosa) and bird cherries (P. avium), born in the confluence of the two species. However, the ecological and, above all, cold tolerance of the ancestor of cultivated sour cherries is higher than that of wild cherries (De Candolle, 1894; Rehder, 1954; Terpó, 1974; Iezzoni et al., 1991; Faust & Surányi, 1997). The cultivation limits are in the northern hemisphere 38-44. degree. The Carpathian Basin, the Balkans and Asia Minor are considered to be the main birthplaces for sour cherries. The genetic and morphological diversity of sour cherries is greater than that of the basic species (Iezzoni et al. 1991; Faust & Surányi, 1997). In the study, 472 sour cherry cultivars were compared based on 7 relative ecological indicators and 3 biological values. Compared to other Prunus species, we mostly found less variability in sour cherries - not counting their salt tolerance (SB). The partial similarity between open pollination (OP), frost tolerance (FR) and disease resistance (DR) - partly true in terms of varieties, but also reflected the effects of purposeful breeding and selection. The cultivars together - in comparison, showed balance, but in the highlighting, the differences of the 3 cultivar groups became significant. Indeed, the differences between the species of the former Hungarian cultural flora are clearly different (Surányi, 2004), which is also the case when comparing a large number of apricot (Surányi, 2014), plum (Surányi, 2015) and peach (Surányi, 2020) varieties.

Phenological Differences, Genetic Diversity, and Population Structure of Genotypes Obtained from Seeds of Kaman-1 Walnut Cultivar

Walnut (Juglans regia L.) is a diploid (2n = 32), deciduous, monoecious, and generally open-pollinated tree with nuts of high nutrient content. In this study, the phenological differences, genetic diversity, and population structure of Kaman-1 and its 79 progenies obtained by open pollination were characterized by ISSR primers and some important phenological traits. As a result of the phenological observations, it was determined that the progenies differ significantly from Kaman-1. Besides, using ISSR primers, walnut genotypes were found to have genetic similarities ranging from 0.52 to 0.99. UPGMA cluster analysis showed that accessions from 2 different groups were classified, and population structure analysis confirmed this finding. Based on the results, a significant variation both phenologically and genetically was found within the walnut accessions. Also, this study confirmed that the progenies obtained from the Kaman-1 walnut cultivar have a quite wide variation and that ISSR primers and phenological traits are an important tool in determining genetic diversity.

Plant variety assessment of garden strawberry based on fruit strength

This article investigates the possibility of obtaining genotypes of garden strawberry with enhanced fruit strength. The creation of species and varieties with the specified feature is expected to improve the quality, transportability and storability of berries. Experiments were performed in 2015–2020 at the collection and breeding plots of the Kokinsky testing station of the Federal Horticultural Research Centre for Breeding, Agrotechnology and Nursery. 29 species of the domestic and foreign selection, 7 choice species, as well as the hybrid seedlings of 22 crossing combinations and 3 open pollination populations of garden strawberries, were investigated. The aim was to identify sources of increased trength and perspective crossing combinations, affording the highest yield of seedlings with firm fruits. The examination of the fruit strength was performed at the stage of optimal maturity. Berries crushing force was determined using a VR-04MS-2-BR balance by applying pressure to the fruits until the first drop of juice appears. The measurement results were converted into international units, i.e., Newtons (1 kg = 9.8 N). The phenotypic evaluation of varieties and species of garden strawberries based on the fruit strength revealed genotypes with the firmest fruits — Kleri, Darselect, Tenira, Selekta, Polka, Tzaritza, Aquarelle, Irma and the 3-366-9 selection. These varieties yield the fruits, which endure the crashing force of over 10 N. In the hybrid progeny, the fruit strength varied within a wide range, and its significant change within the crossing combinations and populations of open pollination was revealed. The Darselect, Cleri, Irma, Tzaritza varieties are the most valuable seed parents in the transmission of the high strength character. Within the research period, the best crossing combination yielding seedlings with fi m fruits were Alfa×Darselect, Festival Romashka×Darselect, Irma×Lyubava, 3-366-9×Kleri, Nashe Podmoskovye×Irma, Festival Romashka×Kleri and open pollination population of the Kleri, Darselect, Tzariza varieties. 42.2 to 60.3 % of hybrid seedlings yielded fruits with the crushing force of over 10 N, and an average value for the families amounted to 9.6–11.2 N.

Pollination Studies on Both Floret and Capitulum Levels in an Oil Seed Crop,Guizotia abyssinica(L.f.) Cass.

Niger,Guizotia abyssinica(L.f.), is an important oilseed crop widely grown in Ethiopia and India, but poor pollination is one of the major constraints in achieving the yield potential of the crop. Our aim was to understand better the pollination biology and role of flower insect visitors in reproduction success. Results indicated that full anthesis occured in the morning between 06.00 and 08.00 h and pollen dehiscence eight to eleven hours after anthesis. Stigma receptivity commenced nine hours after anthesis and lasted for the next 24 h. A total of eighteen insect species representing six families visited Niger flowers, and among these,Apis floreaandA. ceranawere dominant. The flowers were self-incompatible as there was no seed set upon the selfing of floret and selfing of capitulum. The maximum seed set (78.33±0.14%) was noticed when flowers were allowed for open pollination and the lowest was recorded when the whole plant was caged to exclude pollinator visits (0.33±0.67). The time spent byA. ceranaandA. floreawas 1.35±0.48 and 1.83±0.12 seconds per floret, respectively and 9.63±0.69 and 14.9±0.94 seconds per capitulum, respectively.A. ceranaandA. floreawere found to be more efficient pollinators ofG. abyssinica.Introducing bee colonies might greatly improve the yield, and it is also important to conserve bees in the vicinity ofG. abissynicafields during the flowering period. Hence, introducing bee colonies might greatly improve the yield of Niger.

Agronomic performance and economic viability of maize cultivars of open pollination

The open pollination cultivars (VPA) of maize are an alternative of production for a small property, because it presents a good agronomic performance and low production cost, mainly due to the possibility of seed production with low cost. The objective of this research was to evaluate the agronomic performance and economic viability of open pollination cultivars of maize in a low-altitude site in the central region of the state of Rio Grande do Sul. The experiment was conducted during the 2018/2019 crop season, in the experimental area of the Federal University of Santa Maria-UFSM, in the municipality of Santa Maria-RS. The open pollination maize cultivars (SCS 154 Fortuna, SCS 155 Catarina, and SCS 156 Colorado) were used. The experiment consisted of three treatments and four replicates and the experimental design used was that of complete blocks at random. The open pollination cultivars presented an adequate agronomic performance in a low-altitude region in the state of Rio Grande do Sul, associated with the economic viability of the crop in the central region of the state.