The main objective of this research was to study the diversity of maize inbred lines based on phenotypic characters and SSR markers. The research, which was conducted from February to June 2011, was divided into field and laboratory research for molecular analysis. The molecular analysis was conducted at the Biotecnology Laboratory, Faculty of Agriculture, Brawijaya University Malang. The field trial was done in Kandat, Junrejo, Batu. Materials of the research were 35 genotypes of maize. Steps for molecular analysis included: (1) DNA isolation, (2) DNAquality test, (3) PCR SSR, and (4) Visualization of the amplification result. The field trial was done by planting genotypes using a RCBD with 2 replications. Result of the dendogram analysis showed that 35 genotypes of maize were divided into 2 main clusters, A and B, that having 35% similarity level. Result for the analysis of variance showed significant difference among genotypes of maize on the entire of the observed phenotype characters. Heritability (H) ranged from 61.8% to 98.1%. Coefficient of variance ranged from 0.71 to 7.20%. Analysis on the genotypic correlation ranged from 0.06 to 1.0. Numbers of rows per ear showed significant correlation, in which Jaccard's similarity coefficient (r s ) = +0.43.

This research was aim to investigate both direct and indirect effects of some characters related to downy mildew resistance in maize. This information is required to determine the selection criteria on maize breeding program for downy mildew resistance. The research was conducted at Research Station of Agriculture Faculty, University of Brawijaya, from January to April 2012. Five varieties of hybrid maize and five inbreeding lines were employed, and Randomized Complete Block Design with two replications was applied. The result showed revealed that trichome and stomatal density on the upper and lower surface of leaves had positif direct effect and genotipic correlation with downy mildew disease incidence. These characters are qualified as effective selection criteria for resistance to downy mildew. In relation to maize breeding program, low trichome density and stomatal density characters enhance downy mildew resistance.

Most of Indonesian red rice is not grown in dry land. New varieties could be breeded through mutation breeding. This research objective was to evaluate the selection strategy of drought tolerant on red rice. The study was conducted on Ultisol soil in Bangka Belitung Province, Indonesia, in February 2012-February 2015. It consisted of three activities, selection M5, evaluation of selected M5 and evaluation of drought critical period on selected M6. Mutant of M5 was selected and evaluated with polyethylene glycol (PEG) -0.5 MPa and less of soil moisture. Selected M6 was evaluated to observe a critical period of drought stress. Evaluation with PEG produces five superior mutants that more vigor than the elders. Selection on low humidity shows that M5-GR150-1-9 produces higher filled grain and weight filled grain than other mutants and elders. The selected red rice line M5-GR150-1-9-13, has a better tolerance towards drought than its control. It could be obtained such mutant lines which have a high yield, early maturing and drought tolerant from the result of six generations gamma irradiation mutant selection.

This research aimed to investigate the incompatibility levels of controlled cross-pollination in sweetpotato, based on normal seedling percentage and their correlation with seed vigour. The controlled cross-pollination in sweetpotato faces issues due to its cross-incompatibility and selfincompatibility characteristics. Currently, the incompatibility level in sweetpotato is investigated based on the fruit set percentage. However, this criterion lacks the ability in accurately predicting the number of new clones. Therefore, it is essential to study new parameters to create a better investigation of incompatibility in sweetpotato. The materials used in this research consisted of eight sweetpotato clones as female and four sweetpotato clones as male parents. Cross-pollinations were done reciprocally. The experiment was conducted at Indonesian Legume and Tuber Crops Research Institute from April to December 2014. The result showed that totally 5,188 times crossing produced about 25% fruit sets and 10% normal seedlings. The use of normal seedlings percentage as a new parameter in evaluating cross-pollination has apparently seemed to be more effective than the fruit sets percentage method because numbers of new clones could be known accurately. This research revealed that the normal seedling could be used as a new parameter in determining the incompatibility level in sweetpotato controlled cross-pollination.

Accession of red rice does not have the traits of early maturity, drought tolerance and high yield. Mutation is needed to obtain the desired genetic resources. Gamma-ray irradiation is the right method because it was proved capable of producing hundreds of new varieties, which are better than the previous. This study aimed to identify the improvement of early maturity and drought tolerance of red rice mutant to gamma ray irradiation results. The research materials are M4, M5 and M6 strain, which are derived from the Bangka's accession local red rice (Celak Madu, Ruten Puren and radix). The three accession seed have been treated with gamma-ray irradiation doses of 150, 200 and 250 Gray. The results showed gamma ray irradiation dose of 150 Gray and 200 Gray to red rice accession can form a mutant with the character of harvesting time less than 115 days after planting and was more drought tolerant than the previous. M6-GR150-1-9-13 strain was selected as a candidate for early maturity, drought tolerant and high yield mutant.

Abstract

The base-population of the controlled cross breeding is one of the important factors to develop a new improved cultivar. Since the incompatible nature of sweet potato remains a barrier for genetic improvement, therefore it requires a lot of crossed pairs. This study aimed to determine the level of incompatibility among crossing line between high yielding and micronutrient content cultivars. The field experiment conducted at Brawijaya University Research Station, Jatikerto-Malang, during February to August 2015. The North Carolina Design II was applied to sixty pairs controlled cross breeding and their sixty reciprocal pairs of six cultivars for micronutrient content enrichment with ten high yielding cultivars. The observations were made to the cross flowers number, capsules, fruit sets, and seeds number. The level of incompatibility between crossed pairs was determined by the level of fruit set. The result showed that most pairs were compatible (fruit set > 20%) and only few were incompatible (fruit set < 10%). Among six parents with micronutrient content enrichment, two of them, have a high compatibility as as female parents, to all the high yielding cultivars, i.e. BIS OP-61 and Cangkuang. Positioning as a female parent can improve the effectiveness of its selection scheme.

The aim of this research was to describe the potency of superior cultivar upland rice candidates (gogo rice) first generation