Adnan Younis

RNA Interference (RNAi) Induced Gene Silencing: A Promising Approach of Hi-Tech Plant Breeding

RNA interference (RNAi) is a promising gene regulatory approach in functional genomics that has significant impact on crop improvement which permits down-regulation in gene expression with greater precise manner without affecting the expression of other genes. RNAi mechanism is expedited by small molecules of interfering RNA to suppress a gene of interest effectively. RNAi has also been exploited in plants for resistance against pathogens, insect/pest, nematodes, and virus that cause significant economic losses. Keeping beside the significance in the genome integrity maintenance as well as growth and development, RNAi induced gene syntheses are vital in plant stress management. Modifying the genes by the interference of small RNAs is one of the ways through which plants react to the environmental stresses. Hence, investigating the role of small RNAs in regulating gene expression assists the researchers to explore the potentiality of small RNAs in abiotic and biotic stress management. This novel approach opens new avenues for crop improvement by developing disease resistant, abiotic or biotic stress tolerant, and high yielding elite varieties.

Exploitation of induced 2n -gametes for plant breeding

Key MessageEfficient induction of unreduced gamete in different crops and its genetic consequences will open new avenues for plant breeding.AbstractUnreduced gamete formation derived via abnormal meiotic cell division is an important approach to polyploidy breeding. This process is considered the main driving force in spontaneous polyploids formation in nature, but the potential application of these gametes to plant breeding has not been fully exploited. An effective mechanism for their artificial induction is needed to attain greater genetic variation and enable efficient use of unreduced gametes in breeding programs. Different approaches have been employed for 2n-pollen production including interspecific hybridization, manipulation of environmental factors and treatment with nitrous oxide, trifluralin, colchicine, oryzalin and other chemicals. These chemicals can act as a stimulus to produce viable 2n pollen; however, their exact mode of action, optimum concentration and developmental stages are still not known. Identification of efficient methods of inducing 2n-gamete formation will help increase pollen germination of sterile interspecific hybrids for inter-genomic recombination and introgression breeding to develop new polyploid cultivars and increase heterozygosity among plant populations. Additionally, the application of genomic tools and identification and isolation of genes and mechanisms involved in the induction of 2n-gamete will enable increased exploitation in different plant species, which will open new avenues for plant breeding.

FISH and GISH: molecular cytogenetic tools and their applications in ornamental plants.

Key messageThe innovations in chromosome engineering have improved the efficiency of interrogation breeding, and the identification and transfer of resistance genes from alien to native species.AbstractRecent advances in molecular biology and cytogenetics have brought revolutionary, conceptual developments in mitosis and meiosis research, chromosome structure and manipulation, gene expression and regulation, and gene silencing. Cytogenetic studies offer integrative tools for imaging, genetics, epigenetics, and cytological information that can be employed to enhance chromosome and molecular genomic research in plant taxa. In situ hybridization techniques, such as fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH), can identify chromosome morphologies and sequences, amount and distribution of various types of chromatin in chromosomes, and genome organization during the metaphase stage of meiosis. Over the past few decades, various new molecular cytogenetic applications have been developed. The FISH and GISH techniques present an authentic model for analyzing the individual chromosome, chromosomal segments, or the genomes of natural and artificial hybrid plants. These have become the most reliable techniques for studying allopolyploids, because most cultivated plants have been developed through hybridization or polyploidization. Moreover, introgression of the genes and chromatin from the wild types into cultivated species can also be analyzed. Since hybrid derivatives may have variable alien chromosome numbers or chromosome arms, the use of these approaches opens new avenues for accurately identifying genome differences.

Effect of Saccharomyces cerevisiae fermentation on the colorants of heated red beetroot extracts

The quality and flower yield of roses are directly dependent on the balanced application of macro and micronutrients. In the present study, foliar application of macro- and micronutrients was done after every 15 days when new emerging leaves had sprouted after pruning. The results reveal that plants treated with foliar application of micronutrients along with NPK showed significant increase in the growth characteristic like plant height, number of flowers plant-1, bud diameter, flower diameter, fresh and dry weight of flower, flower quality, flower stalk length compared to the application of NPK alone and untreated plants (control). Application of foliar fertilizer (NPK = 15:32:7 + micro power) and NPK (15:32:7) + chelated mix micronutrients gave the highest values compared to the other treatments in both cultivars. Cardinal responded well to micronutrients as compared to Whisky Mac in case of cultivars. Leaf total chlorophyll contents, vase life and the mineral contents (NPK) of leaves were significantly increased as a result of foliar application of micronutrients compared to the control treatment. It was concluded that application of micronutrients along with NPK could improve flower yield and quality of roses. Keywords : Chlorophyll content, NPK percentage, micronutrients, rose African Journal of Biotechnology Vol. 12(7), pp. 702-708

Different Day and Night Temperature Responses in Lilium hansonii in Relation to Growth and Flower Development

Temperature is one of the most important factors that directly affect the possibility and the rate of flower differentiation in many geophytes such as Lilium. In this experiment, different day and night temperatures were used to determine the required day and night temperature for flower bud development in Lilium hansonii. After low temperature exposure for breaking bulb dormancy, the bulbs were planted in pots, and placed in designated growth chambers each with a specific temperature. The plants were exposed to different temperatures for 30 days, and 15 days after planting sample plants were collected in each treatment for observation of flower bud development using the scanning electron microscope (SEM). Responses of plant height, number of leaves, and stem diameter were also measured as affected by difference between day and night temperature (DIF) and average daily temperature (ADT). The results showed that average daily temperature and high day temperature had a direct effect on the quality, quantity, and time required for flower bud development. They also affected the stem elongation, number of leaves, and stem diameter. Higher ADT and DT (25°C) promoted stem elongation and increased leaf unfolding rate (LUR), but with less number of leaves produced. As ADT and DT increased, stem diameter decreases. In lower ADT and DT (15°C) treatment, greater stem diameter and higher number of flower buds (2–7 buds) were produced. Higher ADT and DT promoted early flower bud initiation, but lower number of flower buds with higher possibilities of flower bud abortion, while lower ADT and DT showed slower flower bud initiation and development with higher flower bud formation.

Pre-planting Exogenous Application of Gibberellic Acid Influences Sprouting, Vegetative Growth, Flowering, and Subsequent Bulb Characteristics of 'Ad-Rem' Tulip

Tulip (Tulipa gesneriana L.) is a fascinating bulbous cut flower, and also used for potting, bedding, and border purpose. However, under the sub-tropical climatic conditions, quality tulip flower production is severely affected by its non-uniform bulb sprouting, lack or erratic flowering, small flower stalk, and short vase life. Hence, this study was performed to evaluate the potential of gibberellic acid (GA3) on sprouting, vegetative growth, flowering, flower quality, and vase life, including different bulb characteristics of ‘Ad-Rem’ tulip. Tulip bulbs were dipped in aqueous solution of different GA3 concentrations (0, 50, 75, 100, 125, and 150 mg L-1) for 30 min with Tween-20 (0.01%) as a surfactant. Tulip bulbs treated with 100 mg·L-1 GA3 sprouted in significantly less number of days, exhibited higher sprouting percentage, more plant height, leaf area, leaf chlorophyll, photosynthesis rate, flower stalk length, stalk diameter, and fresh and dry flower stalk weight. Moreover, 100 mg·L-1 GA3 application also decreased overall flower emergence time, increased flower size, produced attractive, glowing, and sturdy flowers with increased quality, and extended the vase life of ‘Ad-Rem’ tulip flowers up to 2.9-folds. However, 150 mg·L-1 GA3 application exhibited better results regarding daughter bulblets per clump with a subsequent increase in bulb diameter, and weight compared to other treatments. Additionally, significant correlation was also found among different growth, flower, and bulb characteristics of GA3-treated tulip plants. Hence, 100-150 mg·L-1 pre-planting exogenous application of GA3 may be effective for quality tulip production under the sub-tropical climatic conditions.

Assessment of biodiversity based on morphological characteristics and RAPD markers among genotypes of wild rose species

Conservation and utilization of the native plant resources is essential for long term sustainability of biodiversity. Wild native resources are adapted to specific and diverse environmental conditions and therefore, these adaptive features can be introduced into modern cultivars either through conventional breeding or advanced molecular genetic techniques. Understanding the genetic make up of the wildly growing plant species and of target desirable genes is a prerequisite for this purpose. Five wild rose ( Rosa L.) genotypes were collected from different locations in northern hilly areas of Pakistan for this study. Different morphological characteristics and PCR based random amplified polymorphic DNA (RAPD) technique was used to find out the diversity and relationship among the genotypes. On morphological basis, Rosa webbiana collected from Muree and Nathia gali showed maximum (83%) similarity, whereas on DNA pattern basis, Rosa brunonii collected from Bansra gali and Sunny bank showed maximum (72%) similarity, while R. webbiana showed maximum diversity among all the species.

Molecular cytogenetic analysis and phylogenetic relationship of 5S and 45S ribosomal DNA in sinomartagon Lilium species by fluorescence in situ hybridization (FISH)

This study was conducted to elucidate the evolution of chromosomal diversification in eight species of Lilium by fluorescence in situ hybridization (FISH) technique using ribosomal DNA probes for the 5S rDNA and 45S rDNA. A phylogenic tree was reconstructed based on the results of the sequence analysis of the non-transcribed spacer (NTS) and inter-transcribed spacer (ITS) regions. The FISH analysis showed Lilium lancifolium (2x) were composed of 3 pairs of 45S rDNA genes on short arms of chromosome # 1, 2, and 7, and 3 pairs on long arms of chromosome # 4, 6, and 11. L. callosum and L. concolor showed the same pattern with L. lancifolium. However, L. dauricum showed 3 pairs of signals on the short arm of chromosome # 1, 2, and 7, and a pair of 45S rDNA signals was detected on the long arms of chromosome # 6 by FISH. The sequence length of the ITS1 and ITS2 regions were 229 bp and 233 bp, respectively. The length of the NTS region, including 5S rDNA segment, was within the range of 474 to 678 bp. According to the phylogenic analysis, L. concolor, L. amabile and L. callosum were closely related, whereas L. lancifolium, diploid and triploid were distantly related.

Ecological analysis of Lilium tsingtauense native in Korea

Korea has large diversity in Lilium germplasm and approximately 15 different species of lilies grow naturally. In present study, a comprehensive evaluation of habitat associations and distribution patterns of Lilium tsingtauense in Korea was carried out. A total of 26 natural habitats of L. tsingtauense were investigated and data regarding its ecological and morphological characteristics under different geological and environmental conditions were collected. During survey it was observed that this species was well distributed nationwide with highly variable altitudes such as Jindo Island (82 m) and Mt. Jiri (1182 m). Most (84%) of natural habitats of this species were found in the northern slopes of mountains and the remainder (15%) habitats were present in the southern regions. Flowers with upward facing had no fragrance and flowering time of this species was in between early July to mid-July. Colonies of Larix leptolepis, as well as 106 other plant species, were mainly found in these natural habitats. The soil was strongly acidic, within the pH range of 4.3-5.3. EC, organic content, total-nitrogen content, and CEC varied among natural habitats. Most of the soils of the natural habitats were sandy loam with low clay ratios. This study can provide baseline information regarding the effective exploitation and use of L. tsingtauense resources for breeding research.

Morphological characterization under different ecological habitats and physical mapping of 5S and 45S rDNA in Lilium distichum with fluorescence in situ hybridization

BackgroundThis study was performed to investigate the phenotypic, karyomorphological, and habitat environment characteristics of Lilium distichum that grows naturally in South Korea. Currently, this species follows limited distribution areas and its natural populations are at the brink of extinction mainly due to fragmentation or destruction its natural habitat.ResultsThis species was distributed between approximately 1,000 and 1,500 m above sea level with an average temperature of 22°C. The soil characteristics surrounding the natural habitats included loamy and silt loam soils having organic matter content (10.82%), pH (5.22), electrical conductivity (EC) (0.37 dS/m), total nitrogen (0.45%), and cation exchange capacity (34.3 cmol+/kg). The peak period of blossoming was between 27 July and 1 August. The maximum number of flowers was observed in Mount Deogyu (2.8), whereas the minimum number of flowers was observed in Mount Jiri (1.3) and Mount Seorak (1.2). Results regarding the number of verticillate leaf, bract counts, and verticillate leaf length and width were highest in Mount Odae, while lowest in the Mount Seorak region. The chromosome complement of L. distichum is 2n = 2x = 24; the length of somatic metaphase chromosomes ranges from 17.01 ± 0.32 μm (chromosome 10) to 32.06 ± 0.35 μm (chromosome 1) with a total length/genome of 261.92 μm. In L. distichum, the presence of 1 pair (two loci) of 5S ribosomal DNA (rDNA) and 8 pairs (16 loci) of 45S rDNA was revealed on metaphase chromosomes. One pair of 5S rDNA signal was observed in interstitial region of long arm of chromosome 3 which co-occurred with 45S rDNA. Among the eight pairs of 45SrDNA, three pairs of 45S rDNA signals were observed in short arm of chromosome (chromosome 2, 6, and 7) which were located close to centromere. The other five pairs of 45S rDNA signals were positioned in the interstitial region of long arm (chromosome 3, 4, 5, 10, and 11).ConclusionsThis study provides baseline information regarding the effective exploitation and use of L. distichum resources for breeding research to be used as cut flower and potted plants.