Papers by khunsa khakwani
Pakistan Journal of Agricultural Research
Maydica, 2019
The present study was carried out to develop doubled haploid lines using in-vivo maternal haploid... more The present study was carried out to develop doubled haploid lines using in-vivo maternal haploid induction technique. The study was aimed at the reliability of haploid seed identification through the R1-nj visual colored marker, identification of spontaneous doubling in tropical germplasm, optimization of colchicine percentage and seedling cutting methods for artificial chromosome doubling and revealing the genetics of newly developed DH-lines. Two tropical haploid inducer lines with 4-6% HIR were used as male parents and crossed with a single hybrid FH-949 as female donor parent. The R1-nj visual colored marker was used to sort haploid from diploid kernels. To check the spontaneous chromosome doubling rate these haploid kernels were grown in the field. In the laboratory, different colchicine percentages and seedling cutting treatments were used to double these maternal haploids. The data for seedling survival and DHo seed formation was collected and generalized linear model GLM wa...
T For the estimation of genetic diversity through cluster analysis forty most promising inbred li... more T For the estimation of genetic diversity through cluster analysis forty most promising inbred lines were evaluated for ten different morphological traits. The field experiment was carried out under randomize complete block design (RCBD) in three replications in the field area of maize research station, Ayub Agriculture Research Institute, Faisalabad, Pakistan. According to the statistical analysis of the morphological traits of the inbred lines, wide variability exists for all the characters studied. All the genotypes were grouped into 10 clusters. The parental combinations of the most of developed promising hybrids of the research station exhibited dissimilarity range around 50%. The genotype 24 seems most diverse among all other genotypes with 60 to 80% dissimilarity. The distribution of genotypes in the study indicated that the geographical origin did not have any bearing on clustering pattern.
The demand for corn in the developing world will double by the end of 2050. The challenges due to... more The demand for corn in the developing world will double by the end of 2050. The challenges due to the climate change are real. Where extreme weather events will become more frequent and climate change projections suggest that large yield losses occur in many regions of the world. Corn is cultivated throughout the world and is a strategic crop: can tolerate high radiation intensities and exhibits high efficiency in the use of water. A framework is needed to design maize ideotypes for site specific condition with the definitions of past, present and future environmental history, and the response of the local material using empirical or mechanistic modeling. The ideotype is a combination of different types of biological traits or the genetic basis that confer enhanced performance for a particular biophysical environment, specific cropping system and end use of the crop. Studies of genotype performance under climate variability always shows that a single trait will never improve plant p...
Maydica, 2020
In this study, fifteen cross combinations evolved from five doubled haploid maize lines, and thre... more In this study, fifteen cross combinations evolved from five doubled haploid maize lines, and three open-pollinated varieties used as testers were evaluated for broad-sense heritability, narrow-sense heritability, heterosis, and heterobeltiosis values during 2017-18. The broad-sense heritability and narrow-sense heritability recorded higher for all the studied traits. Higher broad-sense heritability was recorded for grains per cob (99.6%), grain yield per plant (98.8%), cob length (98.2%), and kernels per cob row (98.1%). Higher narrow-sense heritability was found in grain yield per plant (87.7%), cob height (79.8%), kernel per cob row (79.5%), cob diameter (68.7%) and grains per cob (66.1%). Most of the crosses exhibited very high values of heterosis and heterobeltiosis and ranged from -0.01 to 37.3 % percent for grain yield. The F1 hybrids, L1×T1, L1×T2, L1×T3, L2×T2, L4×T1, L4×T2, L5×T1, L5×T2, L5×T3, L2×T3, L3×T3, and L5×T3 were shown to be the best with very good heterosis and h...
International Journal of Agriculture and Biology, 2016
In maize breeding use of doubled haploids (DH) is very important as these are shortening the time... more In maize breeding use of doubled haploids (DH) is very important as these are shortening the time for development of inbred lines. Inbred lines developed through doubled haploid technology are completely homozygous and homogeneous. These inbred lines could be used for heterosis breeding with increased selection efficacy, reduced efforts for line maintenance, reduced length of breeding cycle and convenient applicability of molecular marker assisted breeding. Haploid induction followed by chromosome doubling are practiced for doubled haploid production. Present research emphasized (i) evaluation of four different inducer lines for in-vivo maternal haploid induction and (ii) effectiveness of chromosome doubling with colchicine and pendimethalin herbicide treatments. Haploid induction was done by Stock-6 and three locally produced inducer lines; (I) Stock-6-BC4, (II) Stock-6×CMST×Ig-gene, (III) (Ig-gene×Stock-6×CMST) × (Stock-6-BC4), which were derivatives of Stock6, CMST and Ig-gene. Stock-6, Stock-6-BC4, Stock-6 × (CMST × Ig-gene) and (Ig-gene × Stock-6 × CMST) × (Stock-6-BC4) had 1.01, 2.38, 8.18 and 7.53% average induction rates, respectively. Maternal haploids were identified by using purple color marker gene (R1-nj). Haploids were subjected to colchicine (0.04% colchicine + 0.5% DMSO) and different pendimethalin treatments (0.66, 0.33, 0.165 and 0.0825 ppm) for doubled haploid induction through chromosome doubling. In colchicne treatment, 3.2% plants survived out of which 37.5% reached to maturity and only 50% of these were partially fertile. At 0.66 ppm pendimethalin treatment, 23.3% plants survived out of which 28.57% reached to maturity and only 16.66% plants were partially fertile. Whereas, 0.33, 0.165, 0.0825 ppm treatment showed survival rate of 26.66, 33.33 and 11.11%, respectively but plants showed 100% sterility with sectoral diploidization. Conclusively, local derivative inducer lines viz. Stock-6 × (CMST × Ig-gene) and (Ig-gene × Stock-6 × CMST) × (Stock-6-BC4) showed satisfactorily higher haploid induction rate. These inducer lines are recommended for their further exploitation in haploid induction. For doubled haploid production, 0.66 ppm pendimethalin treatment was more effective in terms of survival, maturity and fertility comparative to all other studied treatments. This indicates that pendimethalin herbicide (0.66 ppm) is an attractive and cost-effective alternative of colchicine.
British Biotechnology Journal, 2015
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Papers by khunsa khakwani