The editor of this timely book has assembled a team of highly regarded scientists, over 40 contributors, to describe the latest, up-to-date research, theory and applications of this increasingly important area of science.Renowned experts in the field have contributed chapters that describe and discuss some of the most topical aspects of plant genomics. The book is fully illustrated and chapters include comprehensive reference sections.Essential reading for scientists involved in plant genomics and a recommended volume for everyone involved in plant science.

In order to identify quantitative trait loci (QTLs) for leaf senescence and related traits in rice (Oryza sativa L.), we developed two backcross populations, indica/japonica// japonica and indica/japonica//indica, using IR36 as the indica parent and Nekken-2 as the japonica parent. The QTLs were mapped using a set of simple sequence-repeat markers (SSRs) in the BC(1)F(1) population. Senescence was characterized in these plants by measuring the leaf chlorophyll content 25 days after flowering (DAF), the reduction in chlorophyll content (the difference between the chlorophyll content at flowering and at 25 DAF), and the number of late-discoloring leaves per panicle at 25 DAF in five plants from each BC(1)F(2) line. These plants were moved into a temperature-controlled growth cabinet at the time of flowering and allowed to mature under identical conditions. Eleven QTLs were detected in the two populations. The major of QTLs for senescence were found on the short arm of chromosome 6 and on the long arm of chromosome 9. Of these, one QTL on chromosome 6 and two on chromosome 9 were verified by confirming the effects of the genotypes on the phenotypes of the BC(1)F(3) lines. The japonica parent was found to contribute to late senescence at all but one QTL. Based on a comparison of the effects of heterozygotes and homozygotes on the phenotypic values of each QTL genotype, we concluded that the differential senescence observed in the indica-japonica hybrid was not due to over-dominance; rather, it was the result of partial-dominance genes that were donated from either of the parents.

A set of BC 1 F 1 , i.e., indica/japonica//japonica and indica/japonica//indica, were produced to specifically compare the effect of heterozygotes and homozygotes at each QTL locus in an indica-japonica hybrid in rice. Grain shape traits and seedling characteristics were measured, in BC 1 F 1 and BC 1 F 2 , respectively. Five QTLs were detected for grain width on chromosome 1, 2, 5 and 7. Two QTLs were detected for the 1000-grain weight on chromosomes 4 and 5. Three QTLs were detected for the grain thickness on chromosomes 2 and 5. Four QTLs were detected for the seedling weight on chromosomes 5, 6 and 12, in addition to three QTLs for other seedling traits, length of first leaf, seedling height and chlorophyll content, on chromosomes 1, 3 and 6, respectively. In the comparison of marker genotypes of AA, Aa and aa, QTLs were detected either between AA and Aa or between Aa and aa, and there was no case in which Aa was superior to AA and aa. In both analyses, each positive effect was contributed from either one of the parents. So far as the present data concern, it was able to conclude that the high level of heterosis in the current indica-japonica hybrids was manifested by a cumulative partial dominant effect of the heterozygotes at many loci and not by overdominance. Then, the set of QTL data for positive effects are considered to be systematically utilized in breeding of parental lines by using molecular markers.

Experiments were carried out at Rice Research and Training Center during 2009 to 2012 growing seasons. This study aimed at evaluation of some commercial Egyptian rice cultivars and some promising lines against blast disease, identification of effective rice blast resistant genes, and distribution of physiological races and common races of Pyricularia grisea. One hundred and thirty two of P. grisea isolates were collected from rice-cultivating governorates in Egypt, namely Kafr EL-Sheikh (36 isolates), Gharbia (48 isolates), Dakahlia (18 isolates), Sharkia (12 isolates), Damietta (6 isolates) and Beheira (12 isolates). IH race group was the most common race (47.69%), followed by IC (26.58%) and IF (12.15%) groups, While IG, ID and IE (6.06, 6.04 and 1.49%, respectively) were the minor race groups during this study period. The promising line GZ 9057-6-1-3-2 revealed the highest level of resistance against most isolates tested (98.48%) followed by Giza 178 and GZ 9523-2-1-1-1 (96.22% for each). On the other hand, the susceptible rice cultivars, Sakha 101 and Sakha104, were infected with the most tested isolates (25.76 and 61.36 % resistance, respectively). Pi-z-5 gene found in IRBLz5-CA and IRBLz5-CA (R) lines scored the highest effective gene of blast resistance (97.76 and 95.50%, respectively). This gene was followed by pita-2 gene, found in the monogenic line IRBLta2-Re (91.70%). On the other hand, Pia gene found in IRBLa-A and IRBLa-C lines was the lowest effective resistant gene with zero efficacy against the tested isolates. The highest percentage of race groups from the total identified isolates were obtained from Gharbia and Kafr El-Sheikh governorates (36.53 and 27.27%, respectively). On other hand, Damietta governorate had the lowest percentage of race groups (4.56% from the total identified races).

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