Production Of Tetraploid Plants Research Articles

Assessment of mutation caused by colchicine in apple gourd (Praecitrullus fistulosus) based on morphological and biochemical attributes

Apple gourd is a very important vegetable. It has problem of more seeds which increase the dislikeness of customers in the market. Research and development are required to reduce the number of seeds for more consumer acceptability. Colchicine may be used as one of the most potential treatments in the propagation which is used to induce mutation and prevention of microtubule formation during cell division and doubling of chromosomes. In this study Colchicine was used. The seed of Apple gourd was treated with two different concentrations T1 and T2 in comparison with control T0. Treated seeds were sown in polyethene bags in nursery for germination and after 40 days were transplanted in the field. This field experimentation was carried out in a research area of department of horticulture sciences according to complete randomized block design (CRBD). The following parameters were recorded (number of leaves per plant, number of branches per plant, number of flowers per plant, flowering time, number of fruits per plant, fruit yield per plant, fruiting time, fruit weight (g), fruit diameter (mm), leaf area (cm2), vine length (cm) and germination %, leaf area, total proteins, total phenolics and stomata contents, carbohydrates contents, chlorophyll A and chlorophyll B contents). Morphological parameters number of leaves per plant, number of branches per plant, number of flowers per plant, flowering time, number of fruits per plant, fruit yield per plant, fruiting time, fruit weight (g), fruit diameter (mm), leaf area (cm2), vine length (cm) and germination % were increased in (T0). While large number of leaves, thicker branches, broad and large leaves, dark flowers and tasteful and seedless fruits were produced in 0.2% colchicine solution (T2). On the other hand, biochemical or physiological parameters leaf area, total proteins, total phenolics and stomata contents were increased in (T0), carbohydrates contents were increased in (T1), chlorophyll A and chlorophyll B contents were increased in (T2). Overall colchicine had good effect on chromosomes number, morphological and physiological attributes of apple gourd. According to present study 0.2 % of colchicine solution is considered best for the production of tetraploid plants and to induce polyploidy in vegetables.

<i>In vitro</i> induction of tetraploids from <i>Exacum ritigalensis</i> (Gentianaceae)

Exacum ritigalensis (Gentianaceae) (Sinhalese: Binara or Ginihiriya) has a potential to develop as a potted plant by improving the size of the flowers and inflorescence. The aim of the study was to establish an efficient and effec-tive system for the production of tetraploid plants through colchicine treatment. Single nodal cuttings (0.5 cm) from aseptic plantlets were established on Murashige and Skoog basal medium (MS) supplemented with 2 mgL-1BAP and different colchicine concentrations (0, 10, 20, 30, 40 and 50 mg-1). They were kept in different durations (0, 7, 14 21 and 28 days) and transferred into 10ml of MS basal medium containing 2 mgL-1 BAP. After one month, they were transferred to MS medium containing 2mgL-1Indole-3-butyric acid (IBA) for rooting. Then root tips were collected from treated plants to observe chromosome number. Afterwards the selected diploid and tetra-ploid plants were acclimatized and transferred to field to observe the morphological characters. Factorial Com-plete Randomized Design (FCRD) with 10 replicates was used for each treatment and statistical analysis was car-ried out using Duncan’s Multiple Range Test of SAS program (9.1.3).The highest percentage of tetraploid plant-lets (26.6%) was observed from nodal cuttings treated with MS basal medium with 2mgL-1 BAP + 30mgL-1 colchi-cine for seven days. The chromosome number of diploid and tetraploid E. ritigalensis determined as 28 and 56 respectively. Cells of the tetraploid plants were comparatively larger cells than diploids plants. The stomata size of the tetraploid (2.96*2.27 μm2) were larger than those of the diploids (1.94*1.48μm2). Leaf shape of diploids was lanceolate while it was ovate or narrowly elliptic in tetraploids. Flower petals of diploid plants were overlapping along their entire length while in tetraploids flower petals were not overlapping. The plants height was significantly higher in diploid (67.00±9 cm) than in tetraploid (38.00±4 cm). Newly produced polyploids of E. ritigalensis have a potential to popularize as a potted plant in the floriculture trade.

Somaclonal variation and in vitro induced mutagenesis in grapevine

Somaclonal and in vitro mutagen-induced variability was studied in grapevine. Plants of Vitis vinifera cv. Podarok Magaracha were regenerated from leaf explants through somatic embryogenesis. Chromosome counts of root tips was used for screening of regenerated plants. Among 242 studied plants, six (2.5%) tetraploids (2n=4x=76) were identified; all others were diploid (2n=2x=38). Neither chimeral, nor aneuploid plants were observed. Gamma-irradiation (5-100 Gy) increased tetraploid plant formation frequency of primary (7%) and embryogenic calluses (7.6%) and some aneuploid plants were also found. Colchicine treatment was not effective for the production of tetraploid plants. Variability among regenerated plants was also found after field testing.

The Induction of Tetraploid in Crotalaria linifolia Linn..

The production of tetraploid plants in Crotalaria linifolia Linn. was attempted with a view to produce more robust plant for fodder. Seed and seedling treatment with different concentrations of colchicine was tried. Seedling treatment proved to be effective.Size of leaves, flowers, stomata and pollen grains of the tetraploid plants showed enchancement over the diploids. Plant height, raceme length, number of flower per raceme, number of pods, size of pods, seeds per pod were however, lower in tetraploid plants. Pollen fertility in diploid and tetraploid plants was 99.82% and 28.57% respectively.Meiotic observations showed abnormalities such as, univalents, and trivalents at metaphase I, unequal distribution of various combination, laggards at analphase I, II micronuclei at telophase I, II and at tetrad. These irregularities were the major factors for high sterility of pollen grains in induced tetraploid plant of C. linifolia.In having larger leaves and bigger seeds, the tetraploids possesses promising economical features. The lower production of pods and seeds in these plants may be eliminated by selection in later generations of the autotetraploids.