Mohammad Jurail Baloch
Department of Microbiology, Sindh, Agriculture University, Tandojam, Pakistan
Abdul Rahim Lakho
Department of Microbiology, Sindh, Agriculture University, Tandojam, Pakistan
Rahmatullah Rind
Department of Microbiology, Sindh, Agriculture University, Tandojam, Pakistan
Hidayatullah Bhutto
Department of Microbiology, Sindh, Agriculture University, Tandojam, Pakistan
ABSTRACT
According to some estimates, cotton plant sheds about 65 to 70% of its fruiting points. Major percent of shedding in the form of squares, flowers and small bolls, however was attributable to high temperatures. The temperature above 35 ° C have been observed rendering pollen grains inviable, thus unfertilized flowers wither without forming bolls. Conventional methods of selecting heat tolerant cotton genotypes become ineffective due to confounding effects of disease, insect-pest, drought, micro and macro-environment of plant, nutrition and water stresses and others. In that situation, in vitro gametophytic selection in the controlled laboratory conditions is rather a reliable and effective technique that takes care-of all the confounding factors mentioned as above. Four cotton genotypes, all hirsutum types (CRIS-121, CRIS-134, CRIS-168 and NIAB-78) were screened for heat tolerance via in vitro male gametophytic selection technique. The percent of pollen germination and the pollen tube length were considered as selection criteria. Cotton genotypes did not differ in both germination percent and pollen tube length at control temperature of 33 ° C, however, they differed at 36 and 39 ° C. at 36 and 39 ° C, varieties CRIS-134 and CRIS-121 were more heat tolerant than CRIS-168 and NIAB-78 as both the varieties gave higher germination percent and longer pollen tubes. At highest temperature of 39 ° C, CRIS-134 and CRIS-121 gave average of 50 and 45% pollen germination and 19.0 and 13.0 millimeter tube length respectively. The control NIAB-78 however, gave significantly lower germination percent (15%) and smaller (10.0mm) pollen tubes at the same temperature.
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How to cite this article
Mohammad Jurail Baloch, Abdul Rahim Lakho, Rahmatullah Rind and Hidayatullah Bhutto, 2000. Screening of cotton genotypes for heat tolerance via in vitro gametophytic selection technique. Pakistan Journal of Biological Sciences, 3: 2037-2038.
DOI: 10.3923/pjbs.2000.2037.2038
URL: https://scialert.net/abstract/?doi=pjbs.2000.2037.2038
DOI: 10.3923/pjbs.2000.2037.2038
URL: https://scialert.net/abstract/?doi=pjbs.2000.2037.2038
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