Combining ability and genetic parameters analysis for agronomic, yield and its component characters were carried out in rice through line x tester analysis of 20 hybrid rice combinations developed by crossing four Photo-Thermosensitive Genic Male Sterility (PTGMS) lines (females) with five male lines / varieties along with parents and check. The 20 hybrids with nine parents were grown in a randomized complete block design with three replications. The experiments were conducted at RRTC in 2010 and 2011growing seasons. Data analysis of variance for combining ability revealed a significant differences among PTGMS lines for plant height, panicle length, panicle weight and filled grains panicle-1 , indicating the importance of additive genetic variance in the inheritance of these characters. The mean squares due to female PTGMS lines were found non-significant for days to heading, tillers plant-1 , spikelet fertility%, 100-grain weight and grain yield characters, indicating the prevalence of non-additive genetic variance and suggesting the importance of heterosis breeding for improvement of rice. An overall appraised of GCA effects revealed that among females; PTGMS-80 and PTGMS-51 had a good general combiners for most characters. Among PTGMS and the tester lines, PTGMS-80 and the tester line JRL-252 had favorable genes for grain yield and the most of desirable characters under study. The hybrid combinations PTGMS-80 x JRL-252 followed by PTGMS-51 x Giza 177 were the best specific hybrid combinations which have significant values for grain yield with desirable characters.
procedure for micropropagation of Nemaguard peach rootstock was developed using stem nodal segments as explants for in vitro establishment. Hundred percent of explants survived with high proliferation of shoots, growth percentage to survival and average shoot length was obtained on Murashige and Skoog (MS) basal medium supplemented with a combination of 0.5 mg/L 6-benzyl amino purine (BAP) plus 0.2 mg/L indole acetic acid (IAA). The maximum number of proliferated shoots (7.0 shoots/explant) was obtained on MS medium supplemented with 3.0 mg/L BAP + 0.5 mg/L 2-isopentenyladene (2iP). Meanwhile, MS basal medium without growth regulators induced the highest shoot length compared with other treatments. However, shoot elongation decreased with the increase of BAP concentration. Ninety percent of the shoots rooted on MS medium supplemented with 3.0 mg/L indole butyric acid (IBA) to obtain complete plants with the maximum average root number/shoot (5.8). On the other hand, the maximum root length (8.5 and 7.2 cm) was obtained when IBA or naphthalene acetic acid (NAA) were supplemented to half strength MS media at 3.0 mg/L. High survival, over 90%, was obtained when the plantlets were transferred to greenhouse conditions. The Nemaguard peach rootstock cans successfully micropropagated beginning with stem nodal segment without significant damage to mother plant. The in vitro Nemoguard peach rootstocks were planted in Saint Catherine, South Sinai, Egypt where chilling requirements for producing the rootstock seeds are available for commercial production. Hence, it is encouraged to grow Nemaguard peach rootstock under S. Catherine conditions for commercial seed production.
Propolis is a natural resin produced by honeybees colonies in two kinds (Egyptian and Chinese propolis) were tested against some injurious pests i.e. eggs, newly hatched and 4 th instars larvae of the pink bollworm, Pectinophora. gossypiella (Saund.), 4 th instars larvae of the cotton leafworm, Spodoptera. littoralis (Boisd.) and the cowpea aphid, Aphis craccivora (Koch) adults and nymphs. The results showed that; the newly hatched larvae is considered the most susceptible stage of the pink bollworm, followed by 1, 2, 3 and 4-day old eggs especially 1-2 day old eggs. While, the fourth instar larvae were the least susceptible than the other tested stages of P. gossypiella to tested propolis preparations. Fourth instar larvae of the cotton leafworm, S. littoralis were treated by propolis and the mortality rates were recorded at 1, 2, 3, 5 and 7-day after treatments used by the tested preparations of propolis. The propolis exhibited toxicity effect on the 4 th instar larvae of S. littoralis especially at 5-7 days after treatment. Adults and nymphs of the cowpea aphid, A. crassivora were affected and should high susceptibility to the toxicity of the propolis treatments. Collectively, Egyptian honeybee propolis was more effective than Chinese one in all the treatments against the tested pests aforementioned.
This study was conducted at the farm of Sakha Agriculture Research Station during 2011 and 2012 growing seasons using nine parents and 36 hybrid combinations to study the relationship between genetic distances of parental genotypes and heterosis. The genetic distance of parental genotypes was determined by using functional genes markers related to yield traits. The correlation between genetic distance of parental genotypes and heterosis values was detected by determining 36 hybrids performance. The results indicated that the genetic distance was significant and positive correlated with grain yield/plant for midparent and standard heterosis estimates of r=0.46* and r=0.35*, respectively. While the parental genetic distance was not significant correlated with heterosis for some other traits among them: number of productive panicles/plant, 1000-grain weight, fertility percentage% and number of grains/panicle. Thus, the correlation coefficients was not sufficient enough among the parental genotypes for these traits and was not suitable to use molecular potentiality for heterosis prediction.
his investigation was carried out during 2013 and 2014 rice growing seasons at the Experimental Farm of Agriculture Research Station, Sakha, Kafr El-Sheikh, Egypt, to study the magnitude of genotypic variation, the magnitude of both general and specific combining abilities (GCA & SCA) and their interaction with the two years as two different environmental conditions, estimation of the genetic parameters and broad and narrow senses heritability and the potentiality of heterosis expression for agronomic and yield and its components characters. Hybrids with a yield advantage of > 1.5t/ha over the highest yielding check variety Giza 178R were considered as promising. Among 12 hybrid combinations tested, six were most promising with mean performance of grain yield ranging from 11.62 t/ha for large stigma A/Giza 182R to 12.99 t/ha for G46A/Giza 178R. The yield over the best local inbred check, Giza 178 ranged from 1.10 to 2.47 ton ha -1 . Among the four cytoplasmic male sterile (CMS) lines, G46A and IR 58025A were the best general combiners for grain yield. The restorer, Giza 178R was the best general combiner among testers for grain yield and most studied characters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.