Phenology of Flowering and Fruit Set in Snake Fruit (Salacca Sumatrana Becc.)

The Sidimpuan snake fruit ( Salacca sumatrana Becc.) tree flowers throughout the year. However, the fruits are produced seasonally. The level of production is directly related to flowering and fruit set. A low level of fruit formation results in a low number of fruits that can be harvested. A deeper understanding of the phenology of flowering and fruit set in Sidimpuan snake fruit may help solve the problem of low off-season production, and is the focus of this study. The study was conducted in the village of Palopat Maria, a subdistrict of Padangsidimpuan Hutaimbaru, Indonesia. The methodology included surveys and descriptive analysis with direct counting of inflorescences and fruits on each sample plant twice a week over each of three sampling periods (May–August 2016, September–December 2016, and January–April 2017). The results showed that the Sidimpuan snake fruit is a monoecious plant with hermaphrodite flowers. The inflorescences set at the base of the midrib of the fronds every 1.0–1.5 months. The plants had five–six flowering stages, and two–three stages of fruit set were observed. The period between the appearance of new flowers and fruit harvest lasted 5–6 months. The highest average number of flower bunches was observed in the January–April flowering period (6.23/tree) and the lowest was in May–August (5.33/tree, i.e., 14% less). The number of fruit bunches was the highest in May–August (4.37/tree), and the lowest in September–December, and was more than 40% less. Analysis of variance indicated that the flowering period significantly affected the percentage of fruit set. The highest fruit set was 85.5% during May–August, and the lowest was 44.0% during September–December. The average leaf nitrogen content in the flowering period of May–August and September–December was significantly different and higher than that in January–April. The average levels of phosphorus and potassium did not vary significantly throughout the year. The difference in fruit set affected the level of production in each flowering season.

Manipulating ZmEXPA4 expression ameliorates the drought-induced prolonged anthesis and silking interval in maize

Drought poses a major environmental threat to maize (Zea mays) production worldwide. Since maize is a monoecious plant, maize grain yield is dependent on the synchronous development of male and female inflorescences. When a drought episode occurs during flowering, however, an asynchronism occurs in the anthesis and silking interval (ASI) that results in significant yield losses. The underlying mechanism responsible for this asynchronism is still unclear. Here, we obtained a comprehensive development-drought transcriptome atlas of maize ears. Genes that function in cell expansion and growth were highly repressed by drought in 50 mm ears. Notably, an association study using a natural-variation population of maize revealed a significant relationship between the level of α-expansin4 (ZmEXPA4) expression and drought-induced increases in ASI. Furthermore, genetic manipulation of ZmEXPA4 expression using a drought-inducible promoter in developing maize ears reduced the ASI under drought conditions. These findings provide important insights into the molecular mechanism underlying the increase in ASI in maize ears subjected to drought and provide a promising strategy that can be used for trait improvement.

Stigma receptivity in Cashew nut (Anacardium occidentale L.)

The cashew is widely and commercially cultivated throughout the nation for its nut. Cashew is a polygamo – monoecious plant with both male and bisexual flowers developing in same inflorescence. Experimental study was conducted at Kesiary Cashew Plantation Sector, Medinipur as per the guidelines Regional Research Station, Jhargram and National Research Centre of Cashew, Karnataka (2014 – 2018). Changes in stigma receptivity were studied by over 100 panicles chosen at random taken from the commercially cultivated germplasms (WBDC – 4, Kottakerala – 2/97, Dicherla – 2/9, Vetore – 56 and Ullal – 2). The study was continued as for one day before, on the day of flower opening, one day & two days after flowering. It indicates that one day prior to opening & two days after of flowering, stigma receptivity was maximum in the plants of Vetore – 56. But on the day & one day after of flowering it was highest in Dicherla – 2/9. The optimum period of receptivity was at 12 noon on the day of anthesis.

The effect of ethepon treatment on the formation of flower in melon (Cucumis melo L.)

<p class="Abstract">Melon is a potential horticultural crop which the production is increased significantly each year in Indonesia. However, a melon plant that has been widely developed in Indonesia faced a problem due to the high tropical temperature that affected the fall of flower causing failure in fruit production. In addition, the variation of sex expression in melon flower is important for genetic analysis and breeding programs. Ethepon is one of plant chemical growth regulator that is known to change the sex expression of the plant by increasing the number of female flower in monoecious plant especially Cucurbitaceae. This research aimed to analyze the effect of ethepon treatment on the sex determination of melon flower. This study was conducted by 3 stages treatment of ethepon during March – July 2014, namely when 2, 5, and 7 weeks after planting. Split-plot design has been used with the main plots were arranged in a completely randomized design by cultivating different melon cultivars i.e: Melodi Gama 1, Melodi Gama 3, Bartek, and PI 371795. The data were analyzed by F-test and Duncan Multiple Range Test (DMRT) with significance level at 5 % using software SAS 9.3. The result showed that ethepon treatment affected the formation of melon flower by increasing the number of female or hermaphrodite flower and decreasing the number of male flowers, especially in the concentration of 75 ppm and 100 ppm but with different responses by different cultivar.&nbsp;<o:p></o:p></p>

Analysis of flowering gene in palm oil (Elaeis guineensis)

Faizal I, Emdi A. 2017. Analysis of flowering gene in palm oil (Elaeis guineensis). Asian J Agric 1: 53-58. Palm oil has always been an important commodity in Indonesia. The most common species is palm oil, Elaeis guineensis. Palm oil is a monoecious plant with a tendency to be a temporal dioecious. Female flower will be the one that produces palm oil fruit, that later is treated with palm oil while male flower only takes part in the fertilization process. In order to know the ratio between female and male flower tree in a plantation, this study was performed to detect a distinction between female and male flowering gene sequences from DNA sample of E. guineensis. Based on previous study which managed to characterize MADS-box gene of palm oil, a primer was designed and named GmG (Globosa-male-Gaps). The result shows that the primer has the ability to differentiate DNA sequence female and male flower of E.guineensis, Palm oil. However, further studies with full sequence and more samples are needed to find distinctive results between female and male flower sequences as the GmG primer could be used to design a specific marker or primer to detect the presence of female or male flower within a tree.

A note on a seed sterile nutmeg from the secondary center of domestication

A unique nutmeg accession having normal fruit, but with rudimentary, sterile seed and finely packed mace having a human brain like appearance was collected from a farmer’s garden from the secondary center of domestication of the crop and characterized. Seed (female) sterility in a dioecious or emerging monoecious plant like nutmeg is hitherto not recorded and is a novelty. This unique accession is conserved at the germplasm conservatory of tree spices at the ICAR-Indian Institute of Spices Research, Kozhikode, Kerala.

Inheritance of gynoecism in cucumber (Cucumis sativus L.) using genotype GBS-1 as gynoecious parent

The inheritance pattern of gynoecious sex expression in cucumber was studied by utilizing a gynoecious line (GBS-1) and two monoecious lines (Pusa Uday and Punjab Naveen). Crosses were made between gynoecious line (GBS-1) and monoecious lines (Pusa Uday and Punjab Naveen). The F1 and F2 population along with parental lines were evaluated to study the inheritance of this trait. All F1 hybrids showed gynoecious sex in both crosses and in the F2 generation, the observed distribution of plant phenotypes fitted the expected mendelian ratio of 3 (gynocious plant) : 1 (monoecious plant). The segregation of plant sex types suggested monogenic dominant control of gynoecious sex form in cucumber using genotype GBS-1.

New highly polymorphic microsatellite markers for the aquatic angiosperm Ruppia cirrhosa reveal population diversity and differentiation

Ruppia cirrhosa is a clonal monoecious plant phylogenetically associated to seagrass families such as Posidoniaceae and Cymodoceaceae. It inhabits shallow waters that are important for productivity and as a biodiversity reservoir. In this study, we developed 10 polymorphic microsatellite loci for R. cirrhosa. Additionally, we obtained cross-amplification for two microsatellites previously described for Ruppia maritima. These 12 markers were tested in four R. cirrhosa populations from the southwest of Europe. The number of alleles per locus was high for most of the markers, ranging from 4 to 13. Two populations (Sicily and Cádiz) showed heterozygote deficit (p < 0.001). The four populations (Sicily, Murcia, Cádiz, and Tavira) were significantly differentiated (FST ≠ 0; p < 0.001), corroborating the usefulness of these microsatellites on R. cirrhosa population genetics.

Study on Zostera marina L. Seed Germination Ecological Characteristics in Variable Environmental

The paper is mainly concerned with two parts in morphological observation and tissue culture of Eelgrass (Zostera marina L.).The results areas follows: 1.The microstructure of the plant showed that the cell wall exposing to seawater in epidermal cells of leaves was highly thickened, but the other sides were normal. It was also highly thickened in the side exposing to seawater in the epidermal cells of roots and stems. This structure may function as a barrier against toxic ions to enter the epidermal cells. Chloroplasts were found mainly in the epidermal cells, indicating that epidermal cells were main site where photosynthesis occurred. Aerenchyma was found everywhere in the plant which showed the ability of adaptation to submerged life. Anatomical observation of the inflorescence showed that eelgrass was a monoecious plant; the male flower and carpel were alternating arrangement on the inflorescence. SEM photographs of the stamen and the carpel indicated that the carpel had two stigmas; the pollens of the eelgrass were filamentous. All of the above observation showed that eelgrass is able to adapt to submerged life. The explants were dipped in 75%Alcohol for 10 seconds firstly, they were dipped in 1%NaClO 10 minutes, and this was the best way of sterilization than other treatments.