Heterosis and Combining Ability under Favorable and Salinity Stress in Egyptian Bread Wheat

 Generation mean analysis for effect of salinity soil and water was carried out to study days to 50% Tipping, spike length and No. of spikelets/spike. The results indicated that the mean squares of all genotypes were highly significant for three studied traits, reflecting a great wide genetic variability among them. The mean sum of squares due to the general combining ability (GCA) and specific combining ability (SCA) were high significant for days to 50% Tipping and No. of spikelets/spike, but specific combining ability (SCA) was significant for spike length under salinity stress. Heterosis of all crosses over mid parents (H M.P %) and better parent (H B.P %) for days to 50% Tipping, spike length and No. of spikelets/spike were estimated on this study. The most types of general combining ability effect (gi) and specific combining ability effects (Sij) are involved in the inheritance for three traits. Also, data showed that magnitudes of the non-additive genetic variance (σ2D), which were higher than those of additive (σ2A) ones for days to 50% Tipping and No. of spikelets/spike. The results exhibited that the values of heritability in broad senses (h2b.s%) and narrow senses (h2n.s%) were highly for spike length under Favorable, salinity stress and combined data with values of (87.35 and 58.42%) and (85.32 and 72.73%) and (75.70 and 12.83%). Moreover, the values of (h2b.s%) were highly but the values of (h2n.s%) were low for days to 50% Tipping and No. of spikelets/spike under Favorable and salinity stress conditions, respectively. Finally, it could be concluded that the non- additive gene action played a major role in controlling of traits of days to 50% Tipping and No. of spikelets/spike. However, the additive gene action played a major role in controlling of spike length, respectively.

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Keywords: Combining ability, gene action, heritability, heterosis, salinity, wheat

MICROPROPAGATION OF MEDICINAL PLANTS II. WEDELIA CHINENSIS (OSBECK) MERR. | BIONATURE

 

Methods for in vitro micropropagation of Wedelia chinensis by indirect organogenesis via callus were investigated by optimizing the concentrations and combinations of different phytohormones in MS medium. Callus was induced from the leaf explants in MS medium containing BAP and NAA. Callus proliferation with development of associated nodular structures was achieved on subculturing in MS medium fortified with BAP and L-glutamine. Caulogenesis was recorded after the subculture of the nodular light green friable calli on MS basal medium in 2 weeks time. Rhizogenesis was observed 7 days after reinoculation of the shoots in MS basal medium.

No detectable differences were recorded between the donor and in vitro generated plants with regard to biochemical and cytological parameters.

 

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Keywords: Medicinal plant, Wedelia,, Micropropagation.

EFFECT OF MULCHING MATERIAL AND IRRIGATION FREQUENCY ON YIELD AND ROOT-GALL NEMATODE DISEASE OF OKRA (ABELMOSCHUS ESCULENTUS (L.) MOENCH) UNDER DRY SEASON FARMING SYSTEM | BIONATURE

 

Yield and root-gall nematode disease of Okra as affected by mulching material and irrigation frequency were evaluated during 2009 and 2010 dry seasons (January to April). The experiment was layed out in a 3 X 4 factorial arranged in randomized complete block design with 4 replications. Okra variety: "Awgu early" highly susceptible to root-gall nematode, Meloidogyne incognita was planted at 0.3 X 0.3m in an Ultisol naturally infested by the nematode. Results of the two years showed that black polythene mulch and 12hourly irrigation significantly impaired root-gall nematode disease and improved Okra yield (pods). Severe nematode damage and least pod yield occurred on plants mulched with either palm bunch refuse or no mulching material and irrigated 24 or 36 hourly.

 

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Keywords: Irrigation frequency, mulching material,, okra, root-gall nematode disease and yield

EFFECT OF CYTOMIXIS ON MALE MEIOSIS IN DIFFERENT POPULATIONS OF POLYPOGON FUGAX NEES EX STEUD. FROM DISTRICT KANGRA (HIMACHAL PRADESH) | BIONATURE

 

Meiotic studies were carried on four populations of Polypogon fugax from district Kangra (Himachal Pradesh). All the presently worked out populations on the basis of recognized base number x=7, are hexaploid with haploid chromosome number, n=21. The present study reports spontaneous cytomixis in 3 populations of P. fugax more frequently at diakinesis and M-I. In addition to cytomixis, other meiotic abnormalities like interbivalent connections, chromosome stickiness, unoriented bivalents, laggards, etc. have been worked out for the first time resulting in heterogenous sized pollen grains with reduced pollen fertility.

 

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Keywords: Cytomixis, district Kangra, meiotic abnormalities,, Polypogon fugax

AN EFFICIENT IN VITRO MULTIPLE SHOOTING METHOD OF STEVIA REBAUDIANA BERTONI. | BIONATURE

 

The small miracle plant Stevia rebaudiana Bert. is commercially important due to presence of a natural sweetner, stevioside (diterpene glycoside), a potent alternative to sucrose. Poor seed germinability limits its reproduction to only vegetative propagation by stem cuttings. This makes micropopagation most reliable method. Axenically grown cotyledonary leaves produce profuse calli (10mg/lit NAA-0.5mg/lit Kinetin), which subsequently develop microshoots. Vigorous microshooting (max 72.65, microshoots/explant) was noticed at moderate concentrations of Kinetin and BA (Kinetin 3mg/lit- 5mg/lit, BA 0.5mg/lit-3mg/lit) with maximum shoot length in minimum shoot initiation time. Most of such microshoots rooted efficiently (20 roots /shoot; 4cm root length) within 5-6 days of culture at high IBA concentrations (5mg/lit- 10mg/lit). Such efficient microshoots are being tested for their acclimatization and field establishment potential through routine hardening procedures. The objective of the study is to develop an elite line (microshoots) with high regeneration, good field transfer potential with sustained stevioside production.

 

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Keywords: Stevia, Micropropagation, Multiple shooting

Desiccation and Freezing Sensitivity of Selected Groundnut Genotypes for Germplasm Conservation | Asian Basic and Applied Research Journal

 

The Series of experiments were carried out to determined the sensitivity of five groundnut genotypes  which were:  Sodari, Ghibaish, Barberton, ICGV121 and Advance  to desiccation under 7 saturated salt solutions with specific relative humidity at 35ºC and freezing in liquid nitrogen temperature                  (-196ºC) using desorption drying method. The objectives of the study were to quantify seed desiccation and freezing sensitivity and their relations to seed viability. The equilibrium seed water content of desiccated seeds, germination percentages and rates of desiccated and desiccated-frozen seeds, WC50, water activity, water potential, HMFL and their correlations with other parameters were determined. Equilibrium mean water content in gH2Og-1dw was determined gravimetrically when seeds were oven-dried under 105ºC for 24 hrs. Seed desiccation sensitivity, (designated as WC50) was obtained using the Quantal Quadric response model. Freezing sensitivity was determined using high moisture freezing limit (HMFL). The significant increases in seed viability (germination %) with decreases in equilibrium water content observed in this study. All seeds withstand low level of equilibrium water content (below 0.1 gH2Og-1dw) implying that, there were not sensitive to desiccation and freezing as determined by sensitivity indicators (WC50, wa50, Ψ50 and HMFL). In contrast, Barberton, Ghibaish and the Advance line showed less sensitivity to liquid nitrogen (HMFL value of 0.1 gH2Og-1dw) compared to Sodari and ICGV121 (HMFL values of 0.06 and 0.05 gH2Og-1dw, respectively). Correlation analyses indicated that, equilibrium seed water content was positively correlated with seed germination after desiccation and freezing. WC50 was positively correlated with HMFL indicating that the sensitivity of seeds to freezing depends upon its level of desiccation

 

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Keywords: Desiccation, freezing, conservation, groundnut, genotypes

IN VITRO MULTIPLE SHOOT REGENERATION AND ANALYSIS OF GENETIC FIDELITY OF MENTHA PIPERITA L. | BIONATURE

 

An efficient, rapid and reproducible plant regeneration protocol was successfully developed for Mentha piperita L. using nodal explants from naturally field grown plants. Axillary shoot bud proliferation, initiated from nodal explants was cultured on MS (Murashige and Skoog, 1962) medium supplemented with various concentration of 6-benzyladenine (BA) (0.5-3.0 mg/l), Kinetin (KN) (0.5-3.0 mg/l) and 2-isoPentenyladenine (2-iP) (0.5-3.0 mg/l). Maximum numbers of shoots (4.19 ± 0.03) with average length (3.46 ± 0.16) were induced on medium containing 1.0 mg/l BA. Shoots culture was established by repeated sub-culturing the original nodal explant on shoot multiplication medium after each harvest of newly formed shoots. Thus, 20-25 shoots were obtained in 3 months from a single nodal explant. Rooting of shoots was achieved on half strength MS medium supplemented with 1.5 mg/l Indole-3-butyric acid (IBA) and 2% sucrose. Welldeveloped complete plantlets were transferred to plastic pots containing a mixture of (1:1) soil and vermiculite showed 81.13% survived. The hardened plants were evaluated for their genetic fidelity through RAPD markers. Because, genetic uniformity of in vitro raised plants as also a prerequisite for production of quality planting material of Mentha piperita L. This protocol can be used for commercial propagation purposes and to initiate future genetic improvement studies.

 

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