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.

An alcohol extract prepared from the male flower of Eucommia ulmoides Oliv. promotes synoviocyte apoptosis and ameliorates bone destruction in rheumatoid arthritis

Background Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease dominated by synovial hyperplasia and bone destruction. The male flower of Eucommia ulmoides Oliv. (EF) has been shown to exert effects on the inflammation caused by RA. However, how EF affects synoviocyte apoptosis and bone destruction on RA have not been investigated thoroughly. The effects of EF on apoptosis of human fibroblast-like synoviocytes-rheumatoid arthritis (HFLS-RA) cells, osteoclast differentiation of RAW264.7 cells, and bone destruction in a collagen-induced arthritis (CIA) model in rats were explored. Methods First, the main components of EF were identified by high-performance liquid chromatography. In vitro, we investigated the anti-proliferative and pro-apoptotic effects of EF on HFLS-RA cells by immunofluorescence assays, flow cytometry, real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and western blotting; we also investigated how EF influenced the differentiation of RAW264.7 cells into osteoclasts. In vivo, we used a rat model of CIA to investigate the effects of EF on anti-arthritis activity, toe swelling, Arthritis Score, serum levels of metabolic bone factors, and pathologic conditions. Micro-computed tomography was used to scan ankle joints. mRNA and protein expression of factors related to the nuclear factor-kappa B (NF-κB) pathway were determined by RT-qPCR and western blotting, respectively. Results EF inhibited synoviocyte proliferation and promoted apoptosis in a dose-dependent manner. EF inhibited osteoclast differentiation by inhibiting activation of the NF-κB pathway. EF reduced articular inflammation in CIA rats, inhibited the expression of pro-angiogenic factors, and delayed the destruction of articular cartilage and bone. Our data indicated that EF acted via a mechanism related to bone metabolism induced by the NF-κB pathway. Conclusions EF exerts a potential therapeutic effect upon RA. Our research will help to elucidate the potential pharmacologic mechanisms associated with the beneficial effects of EF, and provide an experimental basis for EF application in clinical treatments. Graphical Abstract

Genetic Diversity Analysis in Cucumber (Cucumis sativus L.) Based on Morphological Traits

Evaluation of fifteen diverse genotypes of cucumber was carried out in a randomized complete block design for studying genetic divergence. Presence of wide genetic diversity, among the genotypes studied was confirmed by using Mahalanobis D2 statistics. Based on the interactions genetic distances of cucumber genotypes had grouped into five separate clusters inferring that the genetic divergence between them was quite high. The germplasm were so divergent, that only six genotypes were grouped in cluster V and three genotypes in each cluster I and III. The two genotypes SKY/AC-270-613481 and JB/11-091-613462 were grouped as cluster II and the genotype Tripura local was so divergent in all the characters that they were allotted as a separate group as cluster IV. Cluster mean analysis proclaimed that, genotypes in cluster I recorded maximum value for vine length (3.36 m), number of leaves per plant (43.85), number of branches per plant (12.98), leaf area (144.71 cm2), number of female flowers per plant (20.30), fruiting period (52.20 days), fruit set (89.10 %), average fruit weight (214.72 g), number of fruits per plant (19.00), fruit yield per plant (2.50 kg), fruit yield per ha (31.23 t/ha), rind thickness (2.79 mm) and flesh thickness (3.02 cm), whereas, same cluster I recorded minimum value for traits viz., internodal length (6.55 cm), days to appearance of first male flower (30.34 days), days to appearance of first female flower (31.81 days), node number at which first female flower appeared (4.00), days to first harvest (41.22 days) and number of seeds per fruit (211.69) which are negatively desirable characters in the crop production and crop improvement programme.

SWATH-MS based quantitive proteomics reveal regulatory metabolism and networks of androdioecy breeding system in Osmanthus fragrans

Background The fragrant flower plant Osmanthus fragrans has an extremely rare androdioecious breeding system displaying the occurrence of males and hermaphrodites in a single population, which occupies a crucial intermediate stage in the evolutionary transition between hermaphroditism and dioecy. However, the molecular mechanism of androdioecy plant is very limited and still largely unknown. Results Here, we used SWATH-MS-based quantitative approach to study the proteome changes between male and hermaphroditic O. fragrans pistils. A total of 428 proteins of diverse functions were determined to show significant abundance changes including 210 up-regulated and 218 down-regulated proteins in male compared to hermaphroditic pistils. Functional categorization revealed that the differentially expressed proteins (DEPs) primarily distributed in the carbohydrate metabolism, secondary metabolism as well as signaling cascades. Further experimental analysis showed the substantial carbohydrates accumulation associated with promoted net photosynthetic rate and water use efficiency were observed in purplish red pedicel of hermaphroditic flower compared with green pedicel of male flower, implicating glucose metabolism serves as nutritional modulator for the differentiation of male and hermaphroditic flower. Meanwhile, the entire upregulation of secondary metabolism including flavonoids, isoprenoids and lignins seem to protect and maintain the male function in male flowers, well explaining important feature of androdioecy that aborted pistil of a male flower still has a male function. Furthermore, nine selected DEPs were validated via gene expression analysis, suggesting an extra layer of post-transcriptional regulation occurs during O. fragrans floral development. Conclusion Taken together, our findings represent the first SWATH-MS-based proteomic report in androdioecy plant O. fragrans, which reveal carbohydrate metabolism, secondary metabolism and post-transcriptional regulation contributing to the androdioecy breeding system and ultimately extend our understanding on genetic basis as well as the industrialization development of O. fragrans.

High Temperature-induced Spindle Destabilization Results in Aborted Pollen Production in Populus

High temperature can induce the production of 2n gametes and aborted pollen during microsporogenesis in Populus canescens. However, the mechanism by which high temperature induces pollen abortion remains unknown. Here, pollen abortion was induced by exposing male flower buds of P. canescens to 38 and 41 °C; pollen morphology, meiotic abnormalities, defects of the meiotic microtubular cytoskeleton, and tapetum development were characterized, and expression analysis of the Actin gene was conducted. We found that the dominant meiotic stage, temperature, and duration of treatment significantly affected the percentage of high temperature-induced aborted pollen. Damaged spindle microtubules and depolymerized microtubular cytoskeletons were observed, which resulted in many lagging chromosomes at anaphase Ⅰ and Ⅱ, as well as aneuploid male gametes and micronuclei, generating aborted pollen grains. Tapetum disintegration was also delayed. However, the anther dehisced normally, and some viable pollen grains were released, suggesting that the delayed degradation of the tapetum was not responsible for pollen abortion. A significant reduction in PtActin gene expression was detected in treated cells, indicating that spindle actin was disrupted. The spindle actin appeared to protect cells against chromosome segregation errors during meiosis.

The endemic plant species of Bali Ngemba Forest Reserve, Bamenda Highlands Cameroon, with a new Endangered cloud-forest tree species Vepris onanae (Rutaceae).

We revise and update the records of strict and near endemic species of the Bali Ngemba Forest Reserve, the largest known surviving patch (c. 8 km2 in area) of submontane or cloud forest in the Bamenda Highlands, Cameroon which have lost >96 % of their original forest due to human activities. Nine strict endemics, and 11 near endemics are now documented, a drop from the number recorded after the first survey in 2004, since when five of the provisionally named species have been formally published. We test the hypothesis that a further one of the provisionally named putative Bali Ngemba new species, Vepris sp. A, an 8 - 20 m tall tree from cloud forest in the 1310 - 1600 m altitudinal band, is indeed new to science. We compare it morphologically with other multicarpellate, apocarpous, trifoliolate Cameroon tree species formerly placed in the genus Oricia Pierre until they were subsumed into Vepris by Mziray (1992). These are Vepris trifoliolata (Engl.) Mziray and V. gabonensis (Pierre) Mziray. We conclude that Vepris sp. A is a new undescribed species here named as Vepris onanae. The new species is illustrated, mapped and its conservation status assessed as Endangered using the 2012 IUCN standard due to the threats of habitat clearance from agricultural pressures at its three locations all of which remain formally unprotected. Vepris onanae appears unique among the Guineo-Congolian African oricioid species of Vepris in occurring in cloud forest, the other species, apart from V. renierii of the Albertine Rift, occurring in lowland forest. It also differs in the very broad, (7.8 - ) 11.3 - 18 cm wide leaflets of the flowering stems which have a 6-18(-30) mm long, narrowly triangular acumen (vs leaflets <12 cm wide, acumen absent or short) and in having both subsessile and pedicellate (pedicels 0.25 - 0.3 mm long and 1( - 2) mm long) male flowers (vs male flower pedicels all sessile, or all c. 3 mm long). We report for the first time on stage-dependent leaf heteromorphy in Vepris and characterise a level of sexual dimorphism more advanced than usual in the genus.

Standardization of surface sterilization protocols for culture establishment in banana cv. Karpurachakkarakeli(AAB) male flower budsin vitro

Plant tissue culture is a proven technique for producing banana seeds in large quantities, uniformly and in a short time to support good quality banana seeds. The banana flower meristem can be a potential explant. The banana flower meristem offers the opportunity to regenerate plants with agronomic characteristics. This study aimed to regenerate banana flowers in vitro with different sucrose and BA (Benzyladenine) concentrations after standardized surface sterilization protocols. The study used a Completely Randomized Design (CRD), two factorial designwith surface sterilents and gelling agents. The results showed that the treatmentT15 (Sodium hypochlorite (1%) + HgCl2 (0.1%)) in G1 (0.25% gelrite) recorded the lowest fungal and bacterial contamination (0.00, 0.00) & (0.73, 0.53) respectively, in in vitro cultures of male flower buds of banana cultivar KarpuraChakkarakeli (AAB). While, the combination of BA (4 mgL-1) and sucrose (30 mgL-1) concentration had directly induced organogenesis in banana male flower explants.

Genome-Wide Comparative Analysis of R2R3 MYB Gene Family in Populus and Salix and Identification of Male Flower Bud Development-Related Genes

The MYB transcription factor (TF) family is one of the largest plant transcription factor gene family playing vital roles in plant growth and development, including defense, cell differentiation, secondary metabolism, and responses to biotic and abiotic stresses. As a model tree species of woody plants, in recent years, the identification and functional prediction of certain MYB family members in the poplar genome have been reported. However, to date, the characterization of the gene family in the genome of the poplar’s sister species willow has not been done, nor are the differences and similarities between the poplar and willow genomes understood. In this study, we conducted the first genome-wide investigation of the R2R3 MYB subfamily in the willow, identifying 216 R2R3 MYB gene members, and combined with the poplar R2R3 MYB genes, performed the first comparative analysis of R2R3 MYB genes between the poplar and willow. We identified 81 and 86 pairs of R2R3 MYB paralogs in the poplar and willow, respectively. There were 17 pairs of tandem repeat genes in the willow, indicating active duplication of willow R2R3 MYB genes. A further 166 pairs of poplar and willow orthologs were identified by collinear and synonymous analysis. The findings support the duplication of R2R3 MYB genes in the ancestral species, with most of the R2R3 MYB genes being retained during the evolutionary process. The phylogenetic trees of the R2R3 MYB genes of 10 different species were drawn. The functions of the poplar and willow R2R3 MYB genes were predicted using reported functional groupings and clustering by OrthoFinder. Identified 5 subgroups in general expanded in woody species, three subgroups were predicted to be related to lignin synthesis, and we further speculate that the other two subgroups also play a role in wood formation. We analyzed the expression patterns of the GAMYB gene of subgroup 18 (S18) related to pollen development in the male flower buds of poplar and willow at different developmental stages by qRT-PCR. The results showed that the GAMYB gene was specifically expressed in the male flower bud from pollen formation to maturity, and that the expression first increased and then decreased. Both the specificity of tissue expression specificity and conservation indicated that GAMYB played an important role in pollen development in both poplar and willow and was an ideal candidate gene for the analysis of male flower development-related functions of the two species.

Qualitative and Quantitative Phytochemical Screening of Male Flower Buds of Some Banana Cultivars Grown in Assam

The experiment was conducted in the Department of Horticulture, Biswanath College of Agriculture, Assam Agricultural University, Biswanath Chariali in the period begning from November, 2016 till the end of 2018 with eight different banana cultivars grown in Assam i.e T1: Jahaji (AAA), T2: Amritsagar (AAA), T3: Chenichampa (AAB), T4: Malbhog (AAB), T5: Kachkal (ABB), T6: Manohar (ABB), T7: Bhimkal (BBB), T8: Wild banana (BB). Phytochemical assessment revealed the highest and lowest values of pH in the cultivars of balbisiana group and acuminata group, respectively. The moisture content ranged from 80 to 90 percent; ash content, sucrose content, crude fibre and total carbohydrate content varied in all the cultivars. Sugar content in terms of glucose and fructose were highest in Chenichampa while the lowest glucose content was recorded in Amritsagar. Phosphorus content ranged from 51.98 mg/100g to 14.27 mg/100g while potassium content ranged from 786.40 mg/100g to 427.61 mg/100g. The male flower buds possessed crude protein, starch, anthocyanin, sugars, carbohydrates, proteins, important minerals like phosphorus, potassium, sodium, calcium, magnesium, zinc, iron and anti-nutrients like tannin, saponin and phenolic compounds, but their concentrations varied among the cultivars. Organoleptic taste revealed that the male flower buds of cultivars namely, Bhimkal (BB), Wild banana (BB), Malbhog (AAB) and Kachkal (ABB) were found to be tastiest for consumption as vegetable.