Introgression of Drought Tolerance into Elite Basmati Rice Variety through Marker-Assisted Backcrossing

Drought is one of the major abiotic threat to rice production in the context of climate change.Super Basmati is an elite,fine grain basmati rice variety grown in Punjab,Pakistan.Due to drought sensitive in nature,its yield has been facing an alarming situation in production because of gradual decrease in irrigated water for a couple of years.Three reported novel QTLs for drought tolerance were selected for incorporation into Super Basmati by employing marker assisted selection strategy.IR55419-04 with novel QTLs was used as a donor parent.Foreground selection was performed by applying PCR based QTL linked SSR markers followed by recombinant selection by using 2-4 flanking markers.Background selection was exercised by using polymorphic SSR markers for maximum genome recovery of the Super Basmati.The individuals homozygous at the target QTLs and with maximum background of Super Basmati at the rest of the non-target genome was selected for evaluation of drought tolerance.Under drought stress conditions,the yields of all introgressed lines(ILs)were 44.2%-125.7%higher than recurrent parent.Six superior ILs that are drought tolerant and very similar to Super Basmati in terms of agronomic and grain quality traits are marked for release as drought-tolerant varieties in arid regions or for use in breeding programs of high grain quality and drought-tolerant parents.

Soaking Induced Changes in Chemical Composition, Glycemic Index and Starch Characteristics of Basmati Rice

An attempt was made to determine the qualitative changes in basmati rice （Pusa Basmati 1121, PBl121） during soaking at 40 ℃ to 80 ℃. Soaking temperature had significant effect （a = 0.01） on chemical composition, glycemic index and starch characteristics of rice. Starch content, apparent amylose content, crude protein content and crude fat content in un-soaked rice were found to be 73.24%, 27.26%, 8.79% and 2.56%, respectively, but differences in these traits were observed after soaking. Amylose to amylopectin ratio （Am/Ap） decreased from 0.59 to 0.52 （soaked at 80 ℃）. Crude fibre and crude ash contents increased after soaking. The mineral composition （K, P, S, Ca, Mg, Mn, Fe, Cu and Zn） in soaked rice was found to be 16.46% higher than un-soaked rice at the same degree of polishing. Glycemic index of un-soaked rice was found to be 58.41, but decreased to 54.31 after soaking at 80 ℃. Pasting properties, scanning electron microscope images, and X-ray diffractograms suggested partial gelatinization of starch in the temperature range of 60 ℃ to 80 ℃. Based on qualitative changes in rice （apparent amylose content, Am/Ap ratio and crystallinity rate）, it was concluded that intermediate soakincl temperatures （60 ℃ to 70 ℃） would be useful for soaking of PB1121.

采用basmati恢复系研究水稻‘WA’胞质雄性不育系统的育性恢复的遗传

期望水稻的杂交技术能使水稻生产量大幅度增加，从而促进本国的外贸出口。basmati杂交种的成功培育在很大程度上取决于有效恢复系的可得到性以及该品系育性恢复遗传方面的基础知识。本研究于1998年筛选出278个测交种，以鉴定有效恢复系。

Quantifying Effects of Photoperiod, Temperature and Humidity on Flowering Initiation in Basmati Rice Lines

The results suggested that all the pure Basmati lines or genotypes initiate flowering within a specific range of day length duration and temperature. Delaying the transplanting date did not significantly affect the flowering time of studied Basmati lines. Maximum threshold of daily minimum temperature (MT) was 24°C during both the years. Likewise, maximum threshold of daily day-length (DL) durations was 12 hours and 18 minutes during both the study years. Results showed that the flowering was maximum when the MT and DL values were optimum as depicted by peak of the trend lines, where maximum lines flowered. Maximum flowering initiations took place when DL was about 11 hours and 15 minutes indicating Basmati as short day plant which flowers maximum when day lengths are shorter and dark or night duration is longer. During 2013, 1st date trial showed strong relationship between flowering initiation with dates of flowering during the flowering period as depicted by higher regression (R2 = 0.837) values. In 2nd date trial during the same year, the value is lower (R2 = 0.513) depicting less relationship of flowering initiation with the dates of flowering. The same trend was observed in 2014 trial. In 1st date trial, strong relationship between flowering initiation with dates of flowering during the flowering period as depicted by higher regression (R2 = 0.864) values, was observed. In 2nd date trial during the same year, the value is lower (R2 = 0.1789) depicting very poor relationship of flowering initiation with the dates of flowering, and the same trend (R2 = 0.0544) in 3rd date of trial.

Optimization of Conventional Combine Harvester to Reduce Combine Losses for Basmati Rice (<i>Oryza Sativa</i>)

A study was conducted at PAU Regional Research Station, Gurdaspur (Punjab) to investigate the design and operational parameters of threshing mechanism of conventional combine harvester for basmati crop. This study was aimed to investigate the suitable changes required in the self-propelled conventional combine harvester for harvesting the basmati crop with minimum grain losses. Field evaluation of experiment was carried out to assess the influence of independent design variable i.e., arrangement of spikes (AS) and independent operational parameters such as concave clearance (CC) and cylinder speed (CS). The study was aimed to enumerate various combining losses viz., extent of visible and invisible grain damage and threshing efficiency at different AS, CC and CS levels. The first year data recorded during 2017 were processed for the optimization during 2018. The results of the present study revealed that during 2017, maximum visible and invisible losses was 5.49% ± 0.33% and 28.07% ± 3.21%, respectively whereas after modification, these losses remained only 4.00% ± 0.80% and 24.07% ± 2.86%, respectively. The threshing efficiency remained above 99.31% ± 0.47%, for both years. Thus, optimization of combine harvester was able to save the visible grain damage by 60% to 83% and invisible grain damage by 6% to 16%, respectively during 2018 than the year 2017.

basmati水稻优良基因型的遗传偏差

本研究为了选择出遗传上学上有差异的亲本品系来培育高产basmati品种，考察了61个优良basmati水稻基因型的遗传差异程度和特性。这些基因型来自印度和其他国家；2000年将这些基因型按随机区组设计三次重复栽培。在每个重复中每个基因型栽培3m长的两行，记录了11种农艺性状的数据，然后进行了遗传偏差分析。

Mapping the Expression Profiles of Grain Yield QTL Associated miRNAs in Rice Varieties with Different Grain Size

microRNAs (miRNAs) are key regulatory molecules that fine tune gene expression at the transcriptional and post-transcriptional levels through the RNA silencing pathways. They play an important role in regulating plant growth, development and response to a/biotic stress conditions. Grain yield is a complex trait that is governed by the coordinated action of several genetic and environmental factors. A number of genes and miRNAs have been identified to affect the grain productivity and yield. In this study, we identified the miRNAs that map to grain yield QTLs in rice. The expression variations of these miRNAs and their target transcript were studied across different tissues of three indica rice varieties with different grain morphology. The varieties used include the extra-long and slender grained Pusa Basmati 1 (PB1), medium grain sized IR64 and the short grained Pokkali (PK). The windows for miRNA target correlation were captured and their putative role in regulating rice grain yield is discussed.

Economic outlook of rice crops in Pakistan:a time series analysis (1970-2015)

Background:The basic objective of this study was to examine the relationship between the rice output,its production area,water availability,and agricultural gross domestic product(GDP)of Pakistan.Annual time series data for 1970–2015 were collected from the National Food Security and Research,Economic Survey of Pakistan,and Pakistan Bureau of Statistics(various publications).Methods:Rice crop data were analyzed using the ordinary least square method and the augmented Dickey–Fuller test.Were interpreted using the Johansen cointegration test.Results:Our study revealed the existence of a long-standing relationship between rice output,its production area,and water availability with the agricultural GDP of Pakistan.Regression results indicate that rice output and cultivated area have a significant and positive relationship with agricultural GDP,while water availability has a negative relationship.Conclusions:The study suggests that the government of Pakistan should design new policies and funding schemes for developing and improving water availability.