Browsing by Author "Njiruh, Nthakanio P."
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Item Azolla Fern in Mwea Irrigation Scheme and Its Potential Nitrogen Contribution in Paddy Rice Production(Canadian Center of Science and Education, 2019-11) Oyange, W. A.; Chemining’wa, G. N.; Kanya, J. I.; Njiruh, Nthakanio P.Azolla fern is invasive in Mwea Irrigation Scheme in Kenya and its management in paddy rice fields is a challenge to farmers. A survey was undertaken to establish farmer’s knowledge and potential nitrogen contribution by Azolla in the paddies. The Scheme was stratified into seven sections and a questionnaire administered to 250 farmers. Data were collected on awareness levels, source, trend of infestation, abundance, fertilizer regimes and management practices. Five farms from each of the sections were also sampled for Azolla coverage and tissue N levels analyzed. Survey data were analyzed using SPSS software and interpreted using descriptive statistics. Biomass sampling data were analyzed using SASS and means separated using the least significant differences at P ≤ 0.05. The results demonstrated that Azolla has infested nearly all the paddy farms in Mwea. Azolla invasion occurred more than 10 years ago and coverage per unit area was on a decline and stood at 25%. Water shortage and herbicide use were the main reasons associated with this trend. Azolla is conspicuously noticed at transplanting and weeding times. The presence of Azolla in Mwea is enhanced by widespread use of P and K fertilizers and continuous paddy cropping, thus providing a suitable environment for Azolla growth. Azolla was reported to enhance soil fertility, rice yield and yield components. The maximum Azolla biomass coverage was 14.92 t/ha, with a potential nitrogen contribution of 37.6 kg N/ha. Azolla is invasive in Mwea, widespread, beneficial to paddies and with high potential N contribution.Item Biology of the Cell: Notes(LAP Lambert Academic Publishing, 2014-11) Njiruh, Nthakanio P.After a number of years of teaching, I have used notes which, I feel, can be compiled into condensed and precise note book as a point of reference of those I have taught and those others that would want to benefit from the notes. Cell being the fundamental unit of life need to be well understood by all students taking life sciences. It is for this reason I wish to avail my notes for publication so that, they can be easily be shared by all leaners and scholars. This book can be used as precise learner’s pocket notes. It will serve as a first level entry to studying Cell Biology. This will give the necessary preparation in understanding my other notes in Molecular Cell Biology and Cellular Bio-Engineering. The book will be a good prescription, option to other authors, to all students taking life sciences including Biology, Agriculture, Medicine, Pharmacy, Veterinary among others.Item Biotechnology and Genetic engineering- a key to bio-economy. 3rd National Biosafety Conference(2014-08) Njiruh, Nthakanio P.Biotechnology and Genetic engineering- a key to bio-economy. 3rd National Biosafety Conference, 11th – 14th August, 2014. Presented at Kenyatta International Conference Centre, Nairobi, Kenya.Item The Cell Bio-engineering: Biotechnology Practice Notes(Lambert Academic Publishing, 2016) Njiruh, Nthakanio P.This book is compiled from work and experiences of a number of years of teaching Cell Biology, Genetics and Molecular Biology. Thus, the content included is attested practices written with a practical bio-production approach. It comes in form of precise notes that are recommended reference to those people who are beginning and also advancing their careers in biotechnology practice. Moreover, students and researchers who wish to put biotechnology into practice will find this book a very valuable resource. The book mainly, dowels on cell culture and cellular bio-engineering which is purposely written for greater understanding of cellular products.Item The Cell Division Cycle(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Cell Junctions, Cell Adhesion, and the Extracellular Matrix(University of Embu, 2016-11) Njiruh, Nthakanio P.Item The cell membrane Structure(University of Embu, 2016-11) Njiruh, Nthakanio P.Item The Cell Nucleus(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Cell Signaling(University of Embu, 2016-11) Njiruh, Nthakanio P.Item The Cell Wall(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Chloroplasts(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Cytoplasmic microtubules and Cytoskeleton(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Demarcating day-light-length from temperature effects in PGMS rice using back tracking method.(2014) Njiruh, Nthakanio P.; Qingzhong, XueTwo near isogenic rice lines ZAU11S106 (Photoperiod sensitive genic male sterile) and ZAU11F121(a ZAU11S106 whose PGMS gene has undergone reverse mutation to become a non-PGMS) were used. These two lines were studied to define the effects of temperature and day light length on PGMS gene expression using forward gene expression tracking method. In this method, ZAU11S106 and ZAU11F121 were divided into 8blocks into which they were grown up to mordial stage. This was a growth stage before the pollen matured to become fertile or sterile, a point called critical sterility point (CSP). At this growth stage, the first block was exposed to short day light length (SDLL) treatment. After four (4) days first and second row were put under SDLL treatment. A row was included under the treatment after every four days till the first row headed after which the treatment was withdrawn and all rice allowed to grow up to maturity under long day light length (LDLL) and high temperature growth conditions. The PGMS grown under long day and high temperature growth conditions had higher spikelet sterility than those grown under influence of long daylight length and lower temperature growth conditions. Thus, high temperatures complement photoperiod in inducing sterility in PGMS rice.Item Effect of time of Azolla incorporation and inorganic fertilizer application on growth and yield of Basmati rice(Academic Journals, 2020-03) Oyange, W. A.; Chemining’wa, G. N.; Kanya, J. I.; Njiruh, Nthakanio P.Azolla tissue contains 5% N, which is slowly released into the soil upon decomposition. Timing of incorporation is therefore important for maximum benefit to a crop. The effect of time to incorporate Azolla biomass on growth and yield of rice was investigated in Mwea-Kenya. Treatments consisted of 7.5 t ha -1 Azolla applied at 21 days after transplanting (DAT) and 30 kg N ha Azolla biomass applied at transplanting, 7.5 t ha -1 inorganic N applied in splits at O, 21 and at 55 DAT. There were control treatments without Azolla and without inorganic N application. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Phosphorus and potassium were applied at 50 Kg ha -1 each as P2O5 and K2O. Plant height and tiller numbers were recorded at 21 (rooting/tillering), 32 (tillering), 42 (maximum tillering), 60 (flowering) and 75 DAT (heading) while yield parameters were determined at physiological maturity (120 DAT). Data were analysed using SAS software and means separated using the least significant difference test (p≤0.05). Azolla incorporation at transplanting significantly enhanced panicle m -1 , grain weight and grain yield while incorporating it at 21 DAT only significantly enhanced panicle m -2 . Higher environmental temperatures enhanced Azolla effect. The effect of Inorganic N significantly increased plant height, tiller number, grain weight and spikelets panicle -2 -1 . However, percentage grain filling was reduced. The effect of interaction between Azolla application and inorganic N was significant on spikelets panicle and grain weight. Observations therefore indicate that the effect of Azolla on yield and yield components was more when incorporated at transplaItem Endoplasmic Reticulum (ER)(University of Embu, 2016-11) Njiruh, Nthakanio P.Are elaborate membrane system that divide the cytoplasm of Eukaryotes into multiple components. ER are composed of membranous tubules, vesicles and sacs. This compartmentalization provides a specialized environment that facilitates the various stages in protein biogenesis, modification, sorting, and, ultimately, secretion. The ER is the entry point into the secretory pathway for newly synthesized proteins. Ribosomes dock onto a protein pore in the ER membrane, thereby releasing the nascent polypeptide into the lumen of the ER.Item Evaluation of photoperiod and thermosensitive genic male sterile lines for hybrid rice seeds production in Kenya(2013) Kanya, James I.; Njiruh, Nthakanio P.; Kimani, John M.; Wajogu, Raphael K.; Kariuki, SimonPhoto–thermo-sensitive genic male sterile (P(T)GMS) rice is a new hybrid rice technology that uses prolonged light length and high temperatures to induce sterility. This technology is being introduced in Kenya but such growth conditions are lacking in the tropics. To overcome this, we grew P(T)GMS under greenhouse conditions where day light length was prolonged to 14 hrs using solar illumination and day and night temperatures were maintained above 36Cº and 24ºC respectively. Sterility of P(T)GMS was determined by the level of abortive pollen and seed set rates. Hybrid seeds were produced by crossing three P(T)GMS lines (V1PGM, V2TGM and V3PGM) as female lines with Basmati 370 and Basmati 217 varieties as pollen donors. Under long and normal day lengths and high temperatures, pollen sterility ranged from 99-100% but no seeds were set in PGMS lines. However, TGMS recorded 3% and 2% seed set under similar conditions. Under natural conditions both PGMS and TGMS reverted to fertility. Agronomic evaluation showed outstanding (P<0.01) performance of hybrids over parents in flag leaf length (V2370; 35.8 cm), panicle exsertion (V2217; 8cm) and shorter flowering time (V3217; 85 days) under greenhouse conditions while flag leaf width (V1370; 1.48 cm) and tillering (100) performed better under natural conditions. Percentage seed set positively correlated with flag leaf related traits and flowering days but negatively correlated with panicle length, panicle exsertion and tillering. We conclude that the P(T)GMS lines are adaptable for hybrid rice seed production in Kenya but there is need to review the P(T)GMS lines’ background so as to minimize incompatibility in hybrids.Key words: Oryza sativa, Basmati, PGMS/TGMS, seed technology, pollen sterility.Item Functions of cell surface.(University of Embu, 2016-11) Njiruh, Nthakanio P.Item The Genetics of Molecular Biology:Principles and Applications(LAP Lambert Academic Publishing, 2015-04) Njiruh, Nthakanio P.This book is compiled from work and experiences of a number of years of teaching Cell Biology, Genetics and Molecular Biology. Therefore, the content included is long-time tested practices written with a practical approach. It becomes in form of precise notes, that are recommended reference to those people who are beginning and also advancing their careers in Molecular Biology. Moreover, students and researchers in varied fields of study including Biotechnology, Biochemistry, Cell Biology, Biology, Genetics, Agriculture, Medicine, Pharmacy,Veterinary, Biophysics, Bioinformatics among others, will find this book a very valuable resource.Item The Golgi Complex and Cell Secretion(University of Embu, 2016-11) Njiruh, Nthakanio P.Item Introduction to Cell Biology(University of Embu, 2016-11) Njiruh, Nthakanio P.