Zulqarnain Haider

Effect of Transplanting Dates on Cooking, Milling and Eating QualityParameters of Some Fine and Coarse Grain Rice Lines

In order to elucidate the effects of transplanting date on milling, cooking and eating quality traits of nine coarse grain and ten fine grain indica rice lines under four sowing date treatments were studied. Results suggest that very early transplanting is more damaging to milling and cooking of both, fine as well as coarse grain rice lines as compared to delayed transplanting. Likewise, much delayed transplanting is more destructive for milling and cooking characters in case of fine grain rice lines as compared to coarse grain type rice lines. In case of studied fine grain rice genotypes, head rice recovery was observed maximum when translated at 18th of June. Similarly, cooked grain length was improved significantly in case of fine rice lines with delay in transplanting. Results suggest fine grain rice varieties to be transplanted before onset of July in order to have least broken rice in milled rice. Delayed sowing date, milling quality, total and head rice recovery, cooked grain length and bursting percentages showed different trend with respect to the rice lines. KSK 133 and Basmati 515 showed maximum head rice recovery among coarse and fine grain rice lines respectively. Likewise, PK 8785-1-1 and PK 8671-24-4-1-20 showed maximum cooked grain length among coarse and fine grain rice lines respectively.

Molecular screening of rice ( Oryza sativa L.) germplasm for Xa4 , xa5 and Xa21 bacterial leaf blight (BLB) resistant genes using linked marker approach

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) has now become one of major rice diseases. During recent years, its occurrence has increased in Pakistan, particularly in ‘Kallar tract’ which is well-known for quality rice cultivation. Development of new resistant varieties by utilizing the available resistant gene-pool is most reliable breeding technique for the plant breeders. The present study was conducted to explore the genetic resources regarding presence and absence of BLB resistance genes Xa4 , xa5 and Xa21 through DNA marker technology. Effectiveness of Xa21 followed by xa5 and Xa7 genes has been reported to confer more resistance level for BLB in traditional rice belt of Pakistan. For this purpose, eighty (80) rice genotypes comprising of diverse origin including three isogenic lines viz., IRBB4 (carrying Xa4 ), IRBB5 (carrying xa5 ) and IRBB21 (carrying Xa21 ) as positive resistant gene checks and IR24 (carrying none of these) as negative gene check were genotyped. DNA fingerprinting results indicated the presence of Xa4 gene in 41 entries, while 14 lines were positive for xa5 gene. Only one local line was carrying Xa21 gene along with Xa4 . Thus, the present study will not only be helpful for rice breeders to develop new rice varieties carrying disease resistant genes, but will also provide the donors to incorporate / pyramid disease resistant genes in popular rice varieties like Super Basmati and Basmati 515 which are susceptible to BLB disease. Keywords: Molecular screening, rice germplasm, Xa4, xa5 and Xa21 genes, bacterial leaf blight

Nutritional, Physico-Chemical and Milling Quality Traits in Aromatic Pure Basmati Rice Lines as Affected by Different Transplanting Dates

Basmati is the type of rice (Oryza sativa L.) which is long, slender-grained aromatic rice traditionally from the India and Pakistan. Basmati rice is considered sensitive to photoperiod as well as temperature and is highly affected by these climatic factors resulting in significant yield fluctuations. Therefore, a field experiment was conducted to study the effects of these climatic factors on grain, cooking and nutritional qualities of eight advance pure Basmati rice lines by transplanting these lines at four different dates. The results suggested that all the pure basmati lines or genotypes initiates flowering within a specific range of day length duration and temperature. Delaying the transplanting date did not affect the flowering time of studied basmati lines that indicates the lines were pure basmati in nature and had a strong basmati background. Maximum average yield was observed between 23rd June and 14th of July as depicted by yield data of all the dates. Head rice recovery was increased by delaying the dates of transplanting. Protein and amylose contents were recorded highest when lines were transplanted on 14th of July. Bursting was reduced with the delayed transplanting while cooked grain length showed no significant changes with delay in transplanting. Average grain length, average grain thickness and average grain width also remained unchanged by transplanting delay.

Comparative Efficacy of Different Chemical Treatments for Paddy Blast, Brown Leaf Spot and Bacterial Leaf Blight Diseases in Rice (Oryza Sativa L.)

Paddy blast, brown leaf spot and bacterial leaf blight of rice are the most devastating diseases of rice worldwide causing serious threats to food security. For the purpose field trials were conducted for the evaluation of different available fungicides at Rice Research Institute, Kala Shah Kaku during season of 2016. Application of different fungicide to control the disease and their effect on paddy yield under field condition were studied. The results showed that fungicide application not only controlled the disease but also improved the paddy yield as compared to control. In this study, Amistar Top 325 SC performed best to control the Paddy blast that leaf to high yield. In the case of Brown leaf spot, application of Switch DF 80 WG revealed the lowest incidence of disease along with highest protection value. Similarly, Nativo was most effective to control the Bacterial Leaf Blight incidence. Conclusively, these chemical can be used to control the studied bacterial and fungal diseases for high paddy yield.

Impact of Drought Stress on Some Grain Quality Traits in Rice ( Oryza sativa )

The study was conducted to ascertain the harmful effects of drought stress on grain quality traits in rice. For the purpose, grain shape quality traits of twenty rice genotypes were studied in order to understand the effects of drought stress on these quality traits. The result of analysis of variance clearly indicates that genotypes significantly differ in grain quality traits under both normal as well as drought prone environments. Higher heritability estimates for grain length and length to width ratio under normal and all quality traits under stress environment indicate that these characters are controlled by multiple genes and selection of these characters would be effective at early generation. Results showed that grain length was positively correlated with length to width ratio (0.863* and 0.668*) and negatively correlated with grain width (−0.614** and −0.313**) and grain breadth (−0.321**and −0.030ns) under both normal and stress conditions respectively. Grain width was positively correlated with grain breadth (0.711** and 0.486**) and negatively correlated with length to width ratio (−0.926* and −0.910*) under both conditions respectively. Grain width was highly correlated with yield per plant (0.386** and 0.315**) under both, normal and drought stress respectively while grain breadth was positively correlated (0.553**) only under normal condition. It shows that reduction in grain width has direct effect on grain yield. Under normal condition, yield was positively correlated with grain width (0.386**) and grain breadth (0.552*) indicating that grain width and grain breadth should be considered while screening high yielding genotypes under normal condition and grain width alone should be considered for drought stress among the studies characters.