Bacterial leaf blight resistance in rice: a review of conventional breeding to molecular approach

Breeding for disease resistant varieties remains very effective and economical in controlling the bacterial leaf blight (BLB) of rice. Breeders have played a major role in developing resistant rice varieties against the BLB infection which has been adjudged to be a major disease causing significant yield reduction in rice. It would be difficult to select rice crops with multiple genes of resistance using the conventional approach alone. This is due to masking effect of genes including epistasis. In addition, conventional breeding takes a lot of time before a gene of interest can be introgressed. Linkage drag is also a major challenge in conventional approach. Molecular breeding involving markers has facilitated the characterization and introgression of BLB disease resistance genes. Biotechnology has brought another innovation in form of genetic engineering (transgenesis) of rice. Although, molecular breeding cannot be taken as a substitute for conventional breeding, molecular approach for combating BLB disease in rice is worthwhile given the demand for increased production of rice in a fast growing population of our society. This present article highlights the recent progress from conventional to molecular approach in breeding for BLB disease resistant rice varieties

A Rapid Assessment of the Availability and Use of Obstetric Care in Nigerian Healthcare Facilities

Background: As part of efforts to reduce maternal deaths in Nigeria, pregnant women are being encouraged to give birth in healthcare facilities. However, little is known about whether or not available healthcare facilities can cope with an increasing demand for obstetric care. We thus carried out this survey as a rapid and tactical assessment of facility quality. We visited 121 healthcare facilities, and used the opportunity to interview over 700 women seeking care at these facilities. Findings Most of the primary healthcare facilities we visited were unable to provide all basic Emergency Obstetric Care (bEmOC) services. In general, they lack clinical staff needed to dispense maternal and neonatal care services, ambulances and uninterrupted electricity supply whenever there were obstetric emergencies. Secondary healthcare facilities fared better, but, like their primary counterparts, lack neonatal care infrastructure. Among patients, most lived within 30 minutes of the visited facilities and still reported some difficulty getting there. Of those who had had two or more childbirths, the conditional probability of a delivery occurring in a healthcare facility was 0.91 if the previous delivery occurred in a healthcare facility, and 0.24 if it occurred at home. The crude risk of an adverse neonatal outcome did not significantly vary by delivery site or birth attendant, and the occurrence of such an outcome during an in-facility delivery may influence the mother to have her next delivery outside. Such an outcome during a home delivery may not prompt a subsequent in-facility delivery. Conclusions: In conclusion, reducing maternal deaths in Nigeria will require attention to both increasing the number of facilities with high-quality EmOC capability and also assuring Nigerian women have access to these facilities regardless of where they live

Some measures of facility capacity.

<p>Primary care facilities are synonymous with primary healthcare facilities. This also applies to secondary and tertiary care facilities. Tertiary care facilities have all the necessary infrastructure and resources to provide optimal emergency obstetric care. However, they are very few relative to primary and/or secondary facilities.</p><p>ICU  =  intensive care unit; n  =  sample size.</p>*<p>n = 112; ‡ n = 92.</p

Obstetric history of respondents alongside risk of various pregnancy and neonatal outcomes.

<p>BA  =  Birth attendant; Prob.  =  Probability; CI  =  Confidence interval; NDHS  = 2008 Nigeria Demographic and Health Survey.</p><p>The average birth interval for all reported deliveries was <b>2.9</b> years, and it varied between <b>3.3</b> years for deliveries that occurred before year 2001, and <b>2.5</b> years for births that occurred from 2001.</p

Data on respondent characteristics, delivery plans, transportation to the facility and abortions.

<p>The exchange rate used is $1 =  n156.22 (Nigerian naira), being the mean exchange rate for may 2011. Source: <a href="http://www.oanda.com" target="_blank">www.oanda.com</a>.</p><p>N  =  sample size; DHS  =  Nigeria demographic and health survey 2008; TBA  =  traditional birth attendant; Ave  =  average.</p>*<p>– <b>Means of transport today</b> applies to respondents only.</p>**<p>– <b>Average cost</b> applies to both the respondent and her chaperone or who ever accompanied her (irrespective of how this person traveled).</p

Analysis of recurrent parent genome recovery in marker-assisted backcross breeding program in watermelon

Marker–assisted backcross (MABC) is a breeding technique used to develop improved varieties by transferring a gene or QTL into the genome background of an elite variety after 2-3 generations. It is an advanced way of overcoming challenges facing conventional backcross methods as it speeds up the recurrent parent genome recovery (RPG). In order to develop a Fusarium wilt resistant watermelon variety, MABC was used to incorporate wilt resistant gene from the resistant inbred line CS-19 into the genome of the high yielding but wilt susceptible inbred line BL-14. There was estimation of RPG recovery in earlier generations with the use of polymorphic simple sequence repeat (SSR) markers. A total of 380 SSR markers were tested to identify polymorphism between the parents and 78 of them were found to be polymorphic. Background analysis revealed 74.7 – 94.4 and 86.6 – 96.8 % recovery in BC1F1 and BC2F1 generations, respectively. In the BC2F2 generation, RPG recovery ranged from 95.1 and 96.9 and the average in the selected lines was 96.14 %. This study led to the selection of plants that are similar to the recurrent parent and it showed the usefulness of MABC for the quick recovery of a parental genome in a backcrossing population