Citrus-A case study<br />Chinju Maria Mathew<br />008315<br />
Citrus…???<br />No 1 : Nutritional value and productivity.<br />Origin : 4000 BC in South-East Asia.<br />Family : Rutaceae (Evergreen Trees)<br />Nature : Acidic.<br />Reservoir : Vitamin C, Vitamin B9 and Dietary Fibers.<br />Phytochemicals : Reduces risk of many Chronic diseases.<br />
Millennium Break Through !!!<br />4 decades of research – Poor Practical Results.<br />Micro grafting.<br />Nucellar Embryogenesis.<br />Shoot Meristem Regeneration.<br />My pick…<br />“ Tissue Culture of Citrus Cultivars”<br />
At a glance…<br />Nuclear Institute for Agriculture and Biology.<br />Kinnow-Mandarin, rough Lemon, Sweet Lime,<br /> Gada-dehi, Washington Navel, Grapefruit.<br />Aims :<br /> Production of healthy and vigorous calli.<br /> Regeneration from calli.<br /> Production of Somatic Hybrids.<br />
In Lab…<br />Explants :<br /> Nucellus, Under developed seeds, Seedling leaf, Basal node and Ovary.<br />Cultured on MS medium, supplemented with<br /> BA + Kn + 2,4-D + NAA + IAA+ (Glutamine/Malt extract)<br />Reciprocal Crosses.<br />Seed Characteristics. <br />
To the world…?<br />Success lies on Explant and Medium.<br />Only 2,4-D induced Callusing.<br />BA + 2,4-D => Good Quality Embryogenic Calli.<br />BA + Kn => Shoot and Root Induction.<br />2,4-D+Kn => High Quality Calli.<br />Callus formation on the 10th day – Creamy White.<br />Sub-culturing turned GREEN and into mature embryo.<br />
To the world…?(Cntd)<br />Maturation directly proportional to Dryness of the Medium.<br />Secondary Embryogenesis and Pseudo bulbils formation.<br />Production of Somatic hybrids.<br />Tendency to fruit drop (Kinnow).<br />Gada-dehi, maximum number of healthy seeds.<br />
My point of view…<br />POSITIVES<br /><ul><li>Explant - Nucellus.
Detailed study of plant growth hormones on Explant
Formation of Pseudobulbils and Secondary Embryogenesis.</li></li></ul><li>My point of view…(Contd.)<br />NEGATIVES<br /><ul><li>Nucellus exhibit the phenomenon of Juvenility and delayedfruiting.
Higher concentration of 2,4-D => Browning of medium.
Explant collected from field grown trees induced Contamination.
Notable difference and its explanation in weight of seeds is missing.
Tendency to fruitdrop in hybridplants.</li></li></ul><li>To sum it up…<br />Tissue culture and micro propagation – an integral part of plant transformation.<br />Production of Citrus increased steadily.<br />Research was indeed successful and they came up with variety of explants.<br />Resulted in the propagation of healthy citrus plants.<br />